gecko-dev/parser/htmlparser/tests/html/table05k.html

Table in caption works.
<table border>
  <caption>caption1 <br> text1 <font size=6> text2
    <table>
      <tr>
      <td>cell 1-1
      <td>cell 1-2
      <tr>
      <td>still in
      <td>caption 
    </table>
  <tr>
    <td>cell 2-1-1
    <td>cell 2-1-2
  <tr>
    <td>cell 2-2-1
</table>

last text