Word 2000 does not have table styles. It has table AutoFormats that you can
apply and modify. You can't define custom AutoFormats, but you can select
the default AutoFormat. If you want a style with no borders (and no other
special formatting) you can select Table Normal instead of the default Table
Grid.
Word 2002 introduced table styles, which allow you, in effect, to define a
custom AutoFormat. There is a limit to the formatting you can define and
other limitations as well; see
http://www.shaunakelly.com/word/tablestyles/index.html
Also, another reminder: it's "radio buttons," not "radial buttons."