Not sure I understood what you want, but try this:
<table width="80%" border="1" cellpadding="0" cellspacing="0">
<thead>
<tr style=" width:100%;">
<th> </th>
<th>lun</th>
<th>mardi</th>
<th>mercredi</th>
<th>jeudi</th>
<th>vendredi</th>
<th>Samedi</th>
</tr>
</thead>
<tbody>
{% for i in 0..23) %}
<tr>
<td></td>
<td><a href="">{{ entities[i].id }}</a></td>
<td><a href="">{{ entities[i+24].id }}</a></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
{% endfor %}
</tbody>
</table>