In HTML and XHTML1, the width of the <table> element is the distance from the left border edge to the right border edge.
The table in the figure below could be the result of a style sheet like this:
table { border: outset 10pt;
border-collapse: separate;
border-spacing: 15pt }
td { border: inset 5pt }
td.special { border: inset 10pt } /* The top-left cell */