Right but how would you even display a vertical menu back then? `float: left` was rather bad, so you went back to using tables[0]. Good luck making these responsive.
[0]: and to using dozens of images sliced to fit your table cells, for that cool hover effect as well as round corners. :-)
Why would documents have menus? Menus are for applications.
And there was nothing wrong with tables for layout, especially back then when the alternatives were very brittle.