This diagram shows the effect of the 'separate' value of the 'border-collapse' property.
The diagram shows a three column, two row table whose cells are subject to the separated borders model. The cells themselves have a grey background color and an 'inset' border style, which makes them appear to sink into the page. The cells are separated from each other on all sides by 15pt worth of grey space.
The table itself has a 10pt 'outset' border that gives one the impression the table is rising out of the page.
The full effect of the table is that of a bay window with three panes in two rows.