By default Netscape uses a cell padding of one. Cell padding is the amount of space between the border of the cell and the contents of the cell. Setting a cell padding of zero on a table with borders might look bad because the edges of the text could touch the cell borders. Used to describe the desired width of this table, either as an absolute width in pixels, or a percentage of document width. It can also specify that all the cells in the row should be vertically aligned to the same baseline.
Values are top, middle bottom, and baseline.
This attribute can appear in any table cell and it specifies how many columns of the table this cell should span. This attribute can appear in any table cell and it specifies how many rows of the table this cell should span.