<!DOCTYPE html>
<html>
<head>
<meta charset="iso-8859-15" />
<title>Documento sin título</title>
</head>
<body>
<table width="100%" border="1">
<tr>
<td> </td>
<th colspan="2">COLUMNAS</th>
</tr>
<tr>
<th rowspan="2">FILAS</th>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td>3</td>
<td>4</td>
</tr>
</table>
</body>
</html>