Okay, got it. I have been able to use a nested loop, modifying my data structure to:

$VAR1 = [
  {
    'inner_loop' => [
      {
        'data' => 'one'
      },
      {
        'data' => 'two'
      },
      {
        'data' => 'three'
      }
    ]
  },
  {
    'inner_loop' => [
      {
        'data' => 'four'
      },
      {
        'data' => 'five'
      },
      {
        'data' => 'six'
      }
    ]
  },
  {
    'inner_loop' => [
      {
        'data' => 'seven'
      },
      {
        'data' => 'eight'
      },
      {
        'data' => 'nine'
      }
    ]
  }
];
[download]

And the following template

        <tbody>

              <TMPL_LOOP NAME=DICTIONARY>
              <tr>
              <TMPL_LOOP NAME=inner_loop>
              <td><TMPL_VAR NAME=data></td>
              </TMPL_LOOP>
              </tr>
              </TMPL_LOOP>

        </tbody>
[download]