The PHP and the HTML should each be indented so that they are correct with respect to themselves in source form, irrespective of each other and of outputted form:
<table>
<?php foreach ($rows as $row): ?>
<tr>
<?php if ($row->foo()): ?>
<?php echo $row ?>
<?php else: ?>
Something else
<?php endif ?>
</tr>
<?php endforeach ?>
</table>