You can resize the table and table cells directly by dragging the borders with your left mouse button. To define the size more precisely, use the Cell Properties and Table Properties dialogs instead.

A table or cell dimension can be specified either as a percentage from the width/height of the page, or as an absolute value in pixels. Resizing a table or table cell by dragging preserves the nature of the size property - i.e. if you resize a table, that you have previously set to 50% width, the width remains a relative (%) value.