If you must specify a width, using a percentage is more user-friendly. Border is specified as a number, representing the width of the border in pixels. Because no border is the default, the safest way to have a table without borders is to leave out the border attribute entirely. Alignment attributes for individual cells override any attributes specified for the row as a whole. Horizontal alignment is specified by using the align attribute.
Vertical alignment is specified by using the valign attribute.
The TH and TD tags may have a rowspan attribute, which specifies the number of rows spanned by the cell, and a colspan attribute, which specifies the number of columns spanned by the cell. You will notice that this example also shows a table caption and omits the optional end tags for TR , TH and TD . A table like this will make no sense in a browser which does not render tables. Nested Tables Tables can be nested, which means the contents of a cell can be another complete table. However, the implementation of nested tables in some browsers is flawed.