<style>
.tb
{
width: 1600px;
text-align: center;
border-collapse: collapse;
}
.tb tr td
{
border:1px solid #dcdddd;
}
</style>
<table class="tb" cellpadding="0" cellspacing="0">
<tr>
<td>aaa</td>
<td>bbc</td>
<td>ccc</td>
</tr>
<tr>
<td>aaa</td>
<td>ddd</td>
<td>eee</td>
</tr>
<tr>
<td>ddd</td>
<td>ddd</td>
<td>ddd</td>
</tr>
</table>