<!doctype HTML>
<style>
  table {
    border-collapse: collapse;
  }
  td {
    width:50px;
    height:50px;
    border: 10px solid gray;
  }
</style>
<table>
  <tr>
    <td></td>
    <td></td>
  </tr>
  <tr>
    <td></td>
    <td></td>
  </tr>
</table>
