There can be only one thead and tbody in a table. Both should be direct children of the <table>
tag.
<table>
<thead>
<tr>
<th align="right" colspan="4">
<span class="font-style-bold">SCHEDULE OF RATES</span>
</th>
</tr>
<tr>
<th class="align-left">
<div class="para">
</div>
</th>
<th class="align-left">
<div class="para">
</div>
</th>
<th class="align-left">
<div class="para">
<span class="font-style-bold">Unit</span>
</div>
</th>
<th class="align-left">
<div class="para">
<span class="font-style-bold">Rate $</span>
</div>
</th>
</tr>
</thead>
<tbody>
<tr>
<td rowspan="align-left">
<div class="para">
</div>
</td>
<td rowspan="align-left">
<div class="para">
<span class="font-style-boldunderline">ROOFER</span>
</div>
</td>
<td rowspan="align-left">
<div class="para">
</div>
</td>
<td rowspan="align-left">
<div class="para">
</div>
</td>
</tr>
</tbody>
</table>