diff --git a/src/components/tooltip/Marker.css b/src/components/tooltip/Marker.css
new file mode 100644
index 0000000000..ccbcfad6ad
--- /dev/null
+++ b/src/components/tooltip/Marker.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+.marker-list-value {
+  margin: 0;
+  padding-inline-start: 25px;
+}
+
+/* These styles are useful to make the table well-aligned with its labels in tooltips. */
+.marker-table-value {
+  border-collapse: collapse;
+  margin-block-start: -1px;
+}
+
+.marker-table-value th {
+  text-align: start;
+}
diff --git a/src/components/tooltip/Marker.js b/src/components/tooltip/Marker.js
index f7b49ce383..5a769a7a97 100644
--- a/src/components/tooltip/Marker.js
+++ b/src/components/tooltip/Marker.js
@@ -35,7 +35,7 @@ import {
 import { Backtrace } from 'firefox-profiler/components/shared/Backtrace';
 
 import {
-  formatFromMarkerSchema,
+  formatMarkupFromMarkerSchema,
   getSchemaFromMarker,
 } from 'firefox-profiler/profile-logic/marker-schema';
 import { computeScreenshotSize } from 'firefox-profiler/profile-logic/marker-data';
@@ -62,6 +62,8 @@ import {
   getGCSliceDetails,
 } from './GCMarker';
 
+import './Marker.css';
+
 function _maybeFormatDuration(
   start: number | void,
   end: number | void
@@ -245,7 +247,7 @@ class MarkerTooltipContents extends React.PureComponent<Props> {
                     key={schema.name + '-' + key}
                     label={label || key}
                   >
-                    {formatFromMarkerSchema(schema.name, format, value)}
+                    {formatMarkupFromMarkerSchema(schema.name, format, value)}
                   </TooltipDetail>
                 );
               }
diff --git a/src/profile-logic/marker-schema.js b/src/profile-logic/marker-schema.js
index 3c28eaa4d0..9235ee5d3a 100644
--- a/src/profile-logic/marker-schema.js
+++ b/src/profile-logic/marker-schema.js
@@ -2,6 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 // @flow
+import * as React from 'react';
 import { oneLine } from 'common-tags';
 import {
   formatNumber,
@@ -359,19 +360,64 @@ export function getLabelGetter(
   };
 }
 
+/**
+ * This function formats a string from a marker type and a value.
+ * If you wish to get markup instead, have a look at
+ * formatMarkupFromMarkerSchema below.
+ */
 export function formatFromMarkerSchema(
   markerType: string,
   format: MarkerFormatType,
   value: any
 ): string {
+  if (value === undefined || value === null) {
+    console.warn(
+      `Formatting ${value} for ${markerType} with format ${JSON.stringify(
+        format
+      )}`
+    );
+    return '(empty)';
+  }
+  if (typeof format === 'object') {
+    switch (format.type) {
+      case 'table': {
+        const { columns } = format;
+        if (!(value instanceof Array)) {
+          throw new Error('Expected an array for table type');
+        }
+        const hasHeader = columns.some((column) => column.label);
+        const rows = hasHeader
+          ? [columns.map((x) => x.label || '(empty)')]
+          : [];
+        const cellRows = value.map((row, i) => {
+          if (!(row instanceof Array)) {
+            throw new Error('Expected an array for table row');
+          }
+
+          if (row.length !== columns.length) {
+            throw new Error(
+              `Row ${i} length doesn't match column count (row: ${row.length}, cols: ${columns.length})`
+            );
+          }
+          return row.map((cell, j) => {
+            const { format } = columns[j];
+            return formatFromMarkerSchema(markerType, format || 'string', cell);
+          });
+        });
+        rows.push(...cellRows);
+        return rows.map((row) => `(${row.join(', ')})`).join(',');
+      }
+      default:
+        throw new Error(
+          `Unknown format type ${JSON.stringify((format.type: empty))}`
+        );
+    }
+  }
   switch (format) {
     case 'url':
     case 'file-path':
     case 'string':
       // Make sure a non-empty string is returned here.
-      if (value === undefined || value === null) {
-        return '(empty)';
-      }
       return String(value) || '(empty)';
     case 'duration':
     case 'time':
@@ -392,10 +438,129 @@ export function formatFromMarkerSchema(
       return formatNumber(value);
     case 'percentage':
       return formatPercent(value);
+    case 'list':
+      if (!(value instanceof Array)) {
+        throw new Error('Expected an array for list format');
+      }
+      return value
+        .map((v) => formatFromMarkerSchema(markerType, 'string', v))
+        .join(', ');
     default:
-      console.error(
-        `A marker schema of type "${markerType}" had an unknown format "${(format: empty)}"`
+      console.warn(
+        `A marker schema of type "${markerType}" had an unknown format ${JSON.stringify(
+          (format: empty)
+        )}`
       );
       return value;
   }
 }
+
+// This regexp is used to test for URLs and remove their scheme for display.
+const URL_SCHEME_REGEXP = /^http(s?):\/\//;
+
+/**
+ * This function may return structured markup for some types suchs as table,
+ * list, or urls. For other types this falls back to formatFromMarkerSchema
+ * above.
+ */
+export function formatMarkupFromMarkerSchema(
+  markerType: string,
+  format: MarkerFormatType,
+  value: any
+): React.Element<any> | string {
+  if (value === undefined || value === null) {
+    console.warn(`Formatting ${value} for ${JSON.stringify(markerType)}`);
+    return '(empty)';
+  }
+  if (format !== 'url' && typeof format !== 'object' && format !== 'list') {
+    return formatFromMarkerSchema(markerType, format, value);
+  }
+  if (typeof format === 'object') {
+    switch (format.type) {
+      case 'table': {
+        const { columns } = format;
+        if (!(value instanceof Array)) {
+          throw new Error('Expected an array for table type');
+        }
+        const hasHeader = columns.some((column) => column.label);
+        return (
+          <table className="marker-table-value">
+            {hasHeader ? (
+              <thead>
+                <tr>
+                  {columns.map((col, i) => (
+                    <th key={i}>{col.label || ''}</th>
+                  ))}
+                </tr>
+              </thead>
+            ) : null}
+            <tbody>
+              {value.map((row, i) => {
+                if (!(row instanceof Array)) {
+                  throw new Error('Expected an array for table row');
+                }
+
+                if (row.length !== columns.length) {
+                  throw new Error(
+                    `Row ${i} length doesn't match column count (row: ${row.length}, cols: ${columns.length})`
+                  );
+                }
+                return (
+                  <tr key={i}>
+                    {row.map((cell, i) => {
+                      return (
+                        <td key={i}>
+                          {formatMarkupFromMarkerSchema(
+                            markerType,
+                            columns[i].type || 'string',
+                            cell
+                          )}
+                        </td>
+                      );
+                    })}
+                  </tr>
+                );
+              })}
+            </tbody>
+          </table>
+        );
+      }
+      default:
+        throw new Error(
+          `Unknown format type ${JSON.stringify((format: empty))}`
+        );
+    }
+  }
+  switch (format) {
+    case 'list':
+      if (!(value instanceof Array)) {
+        throw new Error('Expected an array for list format');
+      }
+      return (
+        <ul className="marker-list-value">
+          {value.map((entry, i) => (
+            <li key={i}>
+              {formatFromMarkerSchema(markerType, 'string', value[i])}
+            </li>
+          ))}
+        </ul>
+      );
+    case 'url': {
+      if (!URL_SCHEME_REGEXP.test(value)) {
+        return value;
+      }
+      return (
+        <a
+          href={value}
+          target="_blank"
+          rel="noreferrer"
+          className="marker-link-value"
+        >
+          {value.replace(URL_SCHEME_REGEXP, '')}
+        </a>
+      );
+    }
+    default:
+      throw new Error(`Unknown format type ${JSON.stringify((format: empty))}`);
+  }
+}
diff --git a/src/test/unit/__snapshots__/marker-schema.test.js.snap b/src/test/unit/__snapshots__/marker-schema.test.js.snap
index 760592ac67..ddd50244fd 100644
--- a/src/test/unit/__snapshots__/marker-schema.test.js.snap
+++ b/src/test/unit/__snapshots__/marker-schema.test.js.snap
@@ -1,5 +1,265 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`marker schema formatting supports complex formats 1`] = `
+Array [
+  Array [
+    "url",
+    "http://example.com",
+    <a
+      className="marker-link-value"
+      href="http://example.com"
+      rel="noreferrer"
+      target="_blank"
+    >
+      example.com
+    </a>,
+    "http://example.com",
+  ],
+  Array [
+    "file-path",
+    "/Users/me/gecko",
+    "/Users/me/gecko",
+    "/Users/me/gecko",
+  ],
+  Array [
+    "file-path",
+    null,
+    "(empty)",
+    "(empty)",
+  ],
+  Array [
+    "file-path",
+    undefined,
+    "(empty)",
+    "(empty)",
+  ],
+  Array [
+    "duration",
+    0,
+    "0s",
+    "0s",
+  ],
+  Array [
+    "duration",
+    10,
+    "10ms",
+    "10ms",
+  ],
+  Array [
+    "duration",
+    12.3456789,
+    "12.346ms",
+    "12.346ms",
+  ],
+  Array [
+    Object {
+      "columns": Array [
+        Object {
+          "type": "string",
+        },
+        Object {
+          "type": "integer",
+        },
+      ],
+      "type": "table",
+    },
+    Array [
+      Array [
+        "a",
+        1,
+      ],
+      Array [
+        "b",
+        2,
+      ],
+    ],
+    <table
+      className="marker-table-value"
+    >
+      <tbody>
+        <tr>
+          <td>
+            a
+          </td>
+          <td>
+            1
+          </td>
+        </tr>
+        <tr>
+          <td>
+            b
+          </td>
+          <td>
+            2
+          </td>
+        </tr>
+      </tbody>
+    </table>,
+    "(a, 1),(b, 2)",
+  ],
+  Array [
+    Object {
+      "columns": Array [
+        Object {
+          "label": "a",
+          "type": "string",
+        },
+        Object {
+          "label": "b",
+          "type": "integer",
+        },
+      ],
+      "type": "table",
+    },
+    Array [
+      Array [
+        "b",
+        2,
+      ],
+    ],
+    <table
+      className="marker-table-value"
+    >
+      <thead>
+        <tr>
+          <th>
+            a
+          </th>
+          <th>
+            b
+          </th>
+        </tr>
+      </thead>
+      <tbody>
+        <tr>
+          <td>
+            b
+          </td>
+          <td>
+            2
+          </td>
+        </tr>
+      </tbody>
+    </table>,
+    "(a, b),(b, 2)",
+  ],
+  Array [
+    Object {
+      "columns": Array [
+        Object {
+          "label": "a",
+          "type": "string",
+        },
+        Object {
+          "type": "integer",
+        },
+      ],
+      "type": "table",
+    },
+    Array [
+      Array [
+        "b",
+        2,
+      ],
+    ],
+    <table
+      className="marker-table-value"
+    >
+      <thead>
+        <tr>
+          <th>
+            a
+          </th>
+          <th>
+            
+          </th>
+        </tr>
+      </thead>
+      <tbody>
+        <tr>
+          <td>
+            b
+          </td>
+          <td>
+            2
+          </td>
+        </tr>
+      </tbody>
+    </table>,
+    "(a, (empty)),(b, 2)",
+  ],
+  Array [
+    Object {
+      "columns": Array [
+        Object {
+          "label": "a",
+          "type": "string",
+        },
+        Object {},
+      ],
+      "type": "table",
+    },
+    Array [
+      Array [
+        "b",
+        2,
+      ],
+    ],
+    <table
+      className="marker-table-value"
+    >
+      <thead>
+        <tr>
+          <th>
+            a
+          </th>
+          <th>
+            
+          </th>
+        </tr>
+      </thead>
+      <tbody>
+        <tr>
+          <td>
+            b
+          </td>
+          <td>
+            2
+          </td>
+        </tr>
+      </tbody>
+    </table>,
+    "(a, (empty)),(b, 2)",
+  ],
+  Array [
+    "list",
+    Array [],
+    <ul
+      className="marker-list-value"
+    />,
+    "",
+  ],
+  Array [
+    "list",
+    Array [
+      "a",
+      "b",
+    ],
+    <ul
+      className="marker-list-value"
+    >
+      <li>
+        a
+      </li>
+      <li>
+        b
+      </li>
+    </ul>,
+    "a, b",
+  ],
+]
+`;
+
 exports[`marker schema labels parseErrors errors if looking up into a part of the marker that does not exist 1`] = `
 Array [
   Array [
diff --git a/src/test/unit/marker-schema.test.js b/src/test/unit/marker-schema.test.js
index f92974a982..a2721048d1 100644
--- a/src/test/unit/marker-schema.test.js
+++ b/src/test/unit/marker-schema.test.js
@@ -4,6 +4,7 @@
 // @flow
 import {
   formatFromMarkerSchema,
+  formatMarkupFromMarkerSchema,
   parseLabel,
   markerSchemaFrontEndOnly,
 } from '../../profile-logic/marker-schema';
@@ -177,6 +178,10 @@ describe('marker schema labels', function () {
 });
 
 describe('marker schema formatting', function () {
+  beforeEach(() => {
+    jest.spyOn(console, 'warn').mockImplementation(() => {});
+  });
+
   it('can apply a variety of formats', function () {
     const entries = [
       ['url', 'http://example.com'],
@@ -291,6 +296,56 @@ describe('marker schema formatting', function () {
       ]
     `);
   });
+
+  it('supports complex formats', function () {
+    const entries = [
+      ['url', 'http://example.com'],
+      ['file-path', '/Users/me/gecko'],
+      ['file-path', null],
+      ['file-path', undefined],
+      ['duration', 0],
+      ['duration', 10],
+      ['duration', 12.3456789],
+      [
+        { type: 'table', columns: [{ type: 'string' }, { type: 'integer' }] },
+        [
+          ['a', 1],
+          ['b', 2],
+        ],
+      ],
+      [
+        {
+          type: 'table',
+          columns: [
+            { type: 'string', label: 'a' },
+            { type: 'integer', label: 'b' },
+          ],
+        },
+        [['b', 2]],
+      ],
+      [
+        {
+          type: 'table',
+          columns: [{ type: 'string', label: 'a' }, { type: 'integer' }],
+        },
+        [['b', 2]],
+      ],
+      [
+        { type: 'table', columns: [{ type: 'string', label: 'a' }, {}] },
+        [['b', 2]],
+      ],
+      ['list', []],
+      ['list', ['a', 'b']],
+    ];
+    expect(
+      entries.map(([format, value]) => [
+        format,
+        value,
+        formatMarkupFromMarkerSchema('none', format, value),
+        formatFromMarkerSchema('none', format, value),
+      ])
+    ).toMatchSnapshot();
+  });
 });
 
 describe('getMarkerSchema', function () {
diff --git a/src/types/markers.js b/src/types/markers.js
index ef50242eeb..0fc0c48185 100644
--- a/src/types/markers.js
+++ b/src/types/markers.js
@@ -14,6 +14,7 @@ import type {
 import type { ObjectMap } from './utils';
 
 // Provide different formatting options for strings.
+
 export type MarkerFormatType =
   // ----------------------------------------------------
   // String types.
@@ -58,7 +59,16 @@ export type MarkerFormatType =
   // The decimal should be used for generic representations of numbers. Do not
   // use it for time information.
   // "Label: 52.23, 0.0054, 123,456.78"
-  | 'decimal';
+  | 'decimal'
+  | 'list'
+  | {| type: 'table', columns: TableColumnFormat[] |};
+
+type TableColumnFormat = {|
+  // type for formatting, default is string
+  type?: MarkerFormatType,
+  // header column label
+  label?: string,
+|};
 
 // A list of all the valid locations to surface this marker.
 // We can be free to add more UI areas.