<!DOCTYPE html>
<style>
.header {
line-height: 40px;
}
tr {
break-inside: avoid;
}
</style>
<div style="columns:3; column-fill: auto; height:501px; width: 600px; background-color: yellow;">
<table cellpadding=0 cellspacing=0>
<tr>
<td>
<div class="header">
HEADER<br>HEADER
</div>
</td>
</tr>
<tr><td><div style="height: 399px; width: 1px;"></div></td></tr>
<tr>
<td>
<div class="header">
HEADER<br>HEADER
</div>
</td>
</tr>
<tr><td><div style="height: 399px; width: 1px;"></div></td></tr>
<tr>
<td>
<div class="header">
HEADER<br>HEADER
</div>
</td>
</tr>
<tr>
<td>
<div>Text</div>
<div>Text</div>
<div>Text</div>
<table cellpadding="0" cellspacing="0" style="line-height: 20px; width: 200px;">
<tr>
<td style="width:64px"><strong>Col 1</strong></td>
<td><strong>Col 2</strong></td>
<td><strong>Col 3</strong></td>
<td><strong>Col 4</strong></td>
<td><strong>Col 5</strong></td>
</tr>
<tr>
<td style="height:40px">0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td style="height:40px">0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td style="height:40px">0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td style="height:40px">0</td>
<td>0</td>
<td>0</td>
<td>0</td>
<td>0</td>
</tr>
</table>
</td>
</tr>
</table>
</div>