This attribute can be used in several contexts:
In an XHTML 1.1 table, this attribute should specify the desired width of the entire table and is intended for visual user agents. When the value is a percentage value, the value is relative to the user agent’s available horizontal space. In the absence of any width specification, table width is determined by the user agent. The width value can be either an integer number of pixels or a percentage of the width of the display window.