<!DOCTYPE html>
<style>
td { background-color: green; width: 100px; height: 100px; }
</style>
A table section with opaque background should not be treated as opaque because
it may have transparent areas due to table border-spacing, empty cells, etc.
Passes if the table borders, empty cells are yellow (transparent to show the
background of the underlying div).
<div style="position: absolute; background: yellow">
  <table style="margin: 0px; border-spacing: 10px">
    <tr><td></td></tr>
    <tr><td></td><td></td></tr>
  </table>
</div>