Tables in a material: how not to break the phone

A table is the one block that cannot be made narrower: it has a minimum width of its own, and on a narrow screen it stretches the whole page, adding horizontal scrolling to the entire site.

<div class="pc-scroll">
  <table> ... </table>
</div>

So a table is wrapped in a block with its own scrolling: the table moves, not the page. The "Table" button in the editor does this for you — there is no wrapper to add by hand.