Ti fai 4 img arrotondate e poi le inserisci agli angoli della tabella:

codice:
<table border="0" width="100%" cellspacing="0" cellpadding="0">
  <tr>
    <td width="33%">img1</td>
    <td width="33%"></td>
    <td width="34%">img2</td>
  </tr>
  <tr>
    <td width="33%"></td>
    <td width="33%">testo</td>
    <td width="34%"></td>
  </tr>
  <tr>
    <td width="33%">img3</td>
    <td width="33%"></td>
    <td width="34%">img4</td>
  </tr>
</table>