[html] How can I set the max-width of a table cell using percentages?

<table>
<tr>
<td>Test</td>
<td>A long string blah blah blah</td>
</tr>
</table>

<style>
td{max-width:67%;}
</style>

The above does not work. How can I set the max-width of a table cell using percentages?

I know this is literally a year later, but I figured I'd share. I was trying to do the same thing and came across this solution that worked for me. We set a max width for the entire table, then worked with the cell sizes for the desired effect.

Put the table in its own div, then set the width, min-width, and/or max-width of the div as desired for the entire table. Then, you can work and set width and min-widths for other cells, and max width for the div effectively working around and backwards to achieve the max width we wanted.

#tablediv {
    width:90%;
    min-width:800px
    max-width:1500px;
}

.tdleft {
    width:20%;
    min-width:200px;
}

<div id="tablediv">
  <table width="100%" border="1">
    <tr>
      <td class="tdleft">Test</td>
      <td>A long string blah blah blah</td>
    </tr>
  </table>
</div>

Admittedly, this does not give you a "max" width of a cell per se, but it does allow some control that might work in-lieu of such an option. Not sure if it will work for your needs. I know it worked for our situation where we want the navigation side in the page to scale up and down to a point but for all the wide screens these days.

the percent should be relative to an absolute size, try this :

table {
  width:200px;
}

td {
  width:65%;
  border:1px solid black;
}

<table>
  <tr>
    <td>Testasdas 3123 1 dasd as da</td>
    <td>A long string blah blah blah</td>
  </tr>
</table>
    

Old question I know, but this is now possible using the css property table-layout: fixed on the table tag. Answer below from this question CSS percentage width and text-overflow in a table cell

This is easily done by using table-layout: fixed, but a little tricky because not many people know about this CSS property.

table {
  width: 100%;
  table-layout: fixed;
}

See it in action at the updated fiddle here: http://jsfiddle.net/Fm5bM/4/