W3Schools - Table Width and Height

Text and Images from Slide

table {width: 100%}<br />

th {height: 50px}

The width is in a percentage so that it lets the end user browser adjust the table to fit on a screen.

So it would be 100 percent of a 23" monitor or an iPhone.

Height is in pixels which gives the size for a pixel on either display.

Table width and height sample