Looks to me as if the grayscale settings don't work with tables. (They don't
work with charts, either. It's maddening.) Pure Black and White shows the
text in the tables, though.

If you go to the Design tab and use the Background Styles button to change
the background from dark to light, your text -- assuming it followed the
slide color scheme and used one of the Background/Text colors -- should
change accordingly so it shows up on the light background. Then it will
print in grayscale as well as pure black and white. Then, before you save
the file, go change the background style back to the dark one it was, and
the text will change back to light.

I think I need to put up a page about the background/text colors and how
they work together. Maybe I can do that over the weekend.