Tables provide Web designers ways to add vertical and horizontal structure to a page.
Once you create a table you can easily modify both the appearance and structure of HTML tables. For more advanced layout ideas you can insert a table within a table, adding even more flexibility to your design. Using Dreamweaver, you can easily convert between a table layout and a layer layout. Both tables and layers allow you to control the positioning of page elements, but layers aren't supported in 3.0 and earlier browsers. If your design process requires rapid repositioning of content, you can use layers to lay out a page and then convert the layers to a table for viewing in older browsers.