Comment by peter_l_downs

As igvadaimon wrote below, there's no need for a <table> tag. Instead of:

    <table>
      <tr>
        <td> my div </td>
      </tr>
    </table>

you can do

    <div style="display: table;">
      <div style="display: table-cell;
                  vertical-align: middle;"> my div </div>
    </div>

The inline styling is just for illustrative purposes, of course.