I'm no expert on TT, but it's basically

<table>
[% FOR filename IN walk( dir="/home/username/Desktop" ) %]
    <tr>
      <td>Filename :</td>
      <td>[% filename %]</td>
      <td>[% link( to=> $filename, "Show" ) %]</td>
      <td>[% link( action=>"deletefile" filename => $filename, "Delete
+" )%]</td>
      ...
    </tr>
[% END FOR %]
 </table>
[download]

or, depending on whether the "text content" is supposed to get longer or not, a simple

      <td>[% filename %]</td>
      <td>[% link( to=> $filename ) %]Show</a></td>
[download]

The second approach is worse in my opinion, as it will allow complex and long HTML to be inserted, which is quite inconvenient if the site is ever to be translated.