When you're talking about "redefining the body tag's font attribute", what exactly do you mean?
Do you mean using the style attribute and the font property? Also, which browser causes problems?
Setting the font for the body, either using inline style or a separate style sheet (internal as well as external) should change the font on the whole page. A browser that correctly handles inheritance should display the whole page in that font, no matter if you have tables or other tags.