Fit cell width to content
Solution 1:
I'm not sure if I understand your question, but I'll take a stab at it:
td {
border: 1px solid #000;
}
tr td:last-child {
width: 1%;
white-space: nowrap;
}<table style="width: 100%;">
<tr>
<td class="block">this should stretch</td>
<td class="block">this should stretch</td>
<td class="block">this should be the content width</td>
</tr>
</table>Solution 2:
Setting
max-width:100%;
white-space:nowrap;
will solve your problem.