Table headers are not associated with data cells #2825

What’s broken?

This issue was identified during the Docs accessibility audit on a page containing table-related content.

Audited page:
https://docs.numerique.gouv.fr/docs/0d998bef-1b69-47ce-bd18-83d4d849c734/

In BlockNote tables, users can define row and column headers, and the generated markup uses <th> elements.

However, these headers are not explicitly associated with their related data cells.

There is currently no clear header relationship exposed through:

• scope="col"
• scope="row"
• id / headers relationships for complex tables

Because of this, screen readers may not reliably announce which header applies to each table cell.

This can make table content difficult or impossible to understand for blind users navigating with assistive technologies.

What did you expect to happen?

Table headers should be correctly associated with their related cells.

For simple tables, BlockNote should expose header relationships using scope.

Example:

<table>
  <thead>
    <tr>
      <th scope="col">Name</th>
      <th scope="col">Role</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <th scope="row">Alice</th>
      <td>Designer</td>
    </tr>
  </tbody>
</table>

Steps to reproduce

1. Insert a table
2. Define one or more row or column headers.
3. Inspect the generated table in the DOM.
4. Notice that the table uses <th> elements, but there is no explicit relationship between headers and data cells:
   • no scope="col" on column headers;
   • no scope="row" on row headers;
   • no id / headers relationship for more complex tables.

BlockNote version

0.51.4