Firstly add a class to the :
<tbody>
<tr class="noPadding">
<td><input type="text" name="input1" /></td>
<td><input type="text" name="input2" /></td>
<td><input type="text" name="input3" /></td>
</tr>
</tbody>
Then in your CSS:
.noPadding td { padding: 0; }
If you find you're still getting extra spacing there may be some margins applied to the inputs themselves (depends on your other CSS / browser defaults) if so worth trying:
.noPadding td input { margin: 0; }
Hope this helps.