One of my first questions when I started learn CSS was how replace cellpadding and cellspacing table’s attributes  to separate the styling from the HTML.

The equivalent properties in CSS is padding and border-spacing. However the padding property is applied in the TD tag, not to the TABLE tag.

For example, to achieve the same effect as <table cellpadding="0" cellspacing="0"> you should use the following:

table {
  border-spacing: 0;
}

table td {
  padding: 0;
}

Or, to have an equivalent to <table cellpadding="2" cellspacing="1"> you should use:

table {
  border-spacing: 1px;
}

table td {
  padding: 2px;
}

Source: http://www.frontpagewebmaster.com/m-269102/tm.htm (dead link)