In your first post you created a table in html with a width of 100%.
You can do the same for every cell in a row. Set them all to a fixed pixel value or percentage, except for one column. That one will fill up the remaining space in a row.
Also, you don't have to do it for every row, as all cells in a column will, normally, have the same width.

All this can be done with an element like <td width=100> or using css stylesheets. You know how to use stylesheets as you used it in the original table definition, class="tbl".

The main difference in this approach is that you now set a width instead of trying to get it from a renderer that is not yet in action (as others told you before).