Anche così:
codice:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Documento senza titolo</title>
<style type="text/css">
td {
    border-bottom: 1px #000000 solid;
    border-right: #000000 1px solid;
}
table {
    border-top: 1px #000000 solid;
    border-left: 1px #000000 solid;
}
</style>
</head>

<body>
<table width="500" border="0" cellspacing="0" cellpadding="0">
      <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
      </tr>
      <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
      </tr>
      <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
      </tr>
      <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
      </tr>
</table>

</body>
</html>