Have you tried doing it with one class instead of id?
<td><a href="#" class="is_editable" data-type="text" data-pk="{$alltests.ID}" data-url="labtest-edit-post.php" data-title="Enter Test Type">{$alltests.valuename}</a></td>
<td><a href="#" class="is_editable" data-type="text" data-pk="{$alltests.ID}" data-url="labtest-edit-post.php" data-title="Enter Unit of Measurement">{$alltests.Units}</a></td>
and so on, and then:
$('.is_editable').editable();