Stefan, it's a feature in Word 2000, but not 2003. Word 2000's Autoformat has
a "Formats" list box, where you select the style you want for your table.
Then if has a "Formats to apply" section with radial buttons where you select
"turn off Borders". In 2003 I have to select on "Modify" which opens another
dialogue box, and has the functions of the Tables and Borders toolbar. Then
I can use the "borders box" to remove the borders off the autoformat style.
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."