<html>
<head>
<style type="text/css">
table { table-layout: fixed;
  margin-left: 2em;
  margin-right: 2em;
  border-spacing: 10px;
}
table { border: medium solid red; }
th { border: thin solid green; }
td { border: thin solid blue; }
</style>
</head>
<body>
<table>
<caption>This is a simple 3x3 table</caption>
<tr id="row1">
<th>Header 1 </th>
<td colspan='2'>Cell 1 </td>
<td>Cell 2</td>
</tr>
<tr id="row2">
<th>Header 2 </th>
<td rowspan='2'>Cell 3 </td>
<td colspan='2'>Cell 4</td>
</tr>
<tr id="row3">
<th>Header 3 </th>
<td>Cell 5 </td>
<td>Cell 6 </td>
</tr>
</table>
</body>
</html>