Dear Domenico, Itamar,
thank you for your suggestions, I'm now trying to properly edit the HTML in header / repeated / footer section in Template List to customize my own table.
First tries gave good results, the major issue looks like the table border style which should gather all the elements.

After disabling the editor:
#header
<table style="padding:5px; border-color:#9b0014; background-image: none; float: none; text-align: left; vertical-align: top;" border="1" frame="void" rules="none" width="100%">
<tr>
<td style="width:10%"><b>Type</b></td>
<td style="width:15%"><b>Subtype</b></td>
<td style="width:10%"><b>Phase</b></td>
<td style="width:10%"><b>Source</b></td>
<td style="width:5%"><b>Age</b></td>
<td style="width:15%"><b>Conclusion</b></td>
<td style="width:10%"><b>Notes</b></td>
<td style="width:15%"><b>File</b></td>
<td style="width:10%"><b>Date</b></td>
</tr>
# repeated
<tr>
<td style="width:10%">Type</td>
<td style="width:15%">Subtype</td>
<td style="width:10%">Phase</td>
<td style="width:10%">Source</td>
<td style="width:5%">Age</td>
<td style="width:15%">Conclusion</td>
<td style="width:10%">Notes</td>
<td style="width:15%">File</td>
<td style="width:10%">Date</td>
#footer
</tr>
</table>
I am going to install the Dataform mod as well, but it's better I wait for a more expert admin to perform the installation as Domenico suggested.
All the best
AZ