Così funziona sicuramente, devi adattare le misure alle tue immagini, se sono più grandi di 20px la percentuale del 10% la devi aumentare
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Documento senza titolo</title>
</head>

<body>

<table width="500" border="1" cellspacing="5" cellpadding="5">
  <tr>
    <td width="50%" align="center" valign="middle"><table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td align="center" valign="middle">Descrizione</td>
        <td width="10%" align="right" valign="top">

[img]img.jpg[/img]</p>
          

[img]img.jpg[/img]</p></td>
      </tr>
    </table></td>
    <td width="50%" align="center" valign="middle"><table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td align="center" valign="middle">Data</td>
        <td width="10%" align="right" valign="top">

[img]img.jpg[/img]</p>
          

[img]img.jpg[/img]</p></td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td width="50%" align="center" valign="middle"></td>
    <td width="50%" align="center" valign="middle"></td>
  </tr>
</table>


</body>
</html>