How to make last cell of a row in a table occupy all remaining width

You will need to tell the first two columns not to wrap and give the last column a width of 99%:

<table width="100%">
       <tr>
         <td style="white-space: nowrap;">
           <span>
             COLUMN
           </span>
           <span>
             ONE
           </span>
         </td>
         <td style="white-space: nowrap;">
            COLUMN TWO
         </td>
         <td width="99%">
           LAST
         </td>
       </tr>
     </table>

Edit: You should put that all styles / presentation in (external…) css.

Using classes for the columns (you could use css3 selectors like nth-child() instead if you only target modern browsers):

html:

<tr>
  <td class="col1">
  // etc

css:

.col1, .col2 {
  white-space: nowrap;
}
.col3 {
  width: 99%;
}