border-spacing

The border-spacing CSS property specifies the distance between the borders of adjacent cells (only for the separated borders model). This is equivalent to the cellspacing attribute in presentational HTML, but an optional second value can be used to set different horizontal and vertical spacing.
 
The border-spacing value is also used along the outside edge of the table, where the distance between the table’s border and the cells in the first/last column or row is the sum of the relevant (horizontal or vertical) border-spacing and the relevant (top, right, bottom, or left) padding on the table.
 
This property applies only when border-collapse is separate.

Syntax

border-spacing: length /* one-value syntax */
border-spacing: horizontal vertical /* two-value syntax */
border-spacing: inherit

<!DOCTYPE HTML>
<html>
        <head>
        <title>CSS Tutorials</title>
        <style type="text/css">
table {
	border-spacing: 10px 5px;
}
</style>
        </head>
        <body>
        <table border="1">
          <tr>
            <td> 1 </td>
            <td> 2 </td>
          </tr>
          <tr>
            <td> 3 </td>
            <td> 4 </td>
          </tr>
          <tr>
            <td> 5 </td>
            <td> 6 </td>
          </tr>
        </table>
</body>
</html>

Output :