I'm pretty sure that's just how tables work; they stretch when there's too much content in one of their cells.
Try putting a <div> inside your <td> and apply the width and overflow properties to that instead.
Addendum:
Your table has a CSS width property of 150px while the div has a percentage, %100. Try giving the <div> a non-percentage width...
<table>
<tr>
<td>
<div style="150px;">
<!-- wtv -->
</div>
</td>
</tr>
</table>
Or try putting the whole <table> in a <div> with a fixed width...
<div style="width:150px">
<table>
<!-- wtv -->
</table>
</div>
... lastly, I'd advise that you put your CSS in an external .css file ;)