HTML/CSS/Basic Attributes/border
"border" sets the thickness in pixels of the border around an element
<HTML>
<head>
<Title>Example For border</Title>
</head>
<BODY>
<table width="500" border="10">
<tr>
<td>www.wbex.ru in a cell</td>
</tr>
</table>
</BODY>
</HTML>