If the diameter difference is 3/8" and it's centered on the table top than that is only 3/16" all the way around which should be fine.

Thanks Annie. I appreciate that. It doesn't seem that noticeable. I just wondered if people usually have them cut to exact size or slightly smaller.

" I can buy 34" glass tops ready made. The 24 inch tables are actually 23 5/8". So is it okay for the glass to be 3/8" larger than the table tops,"

Maybe my math is off, but...

glass is 34"
table is 23 5/8"

There is more than a 3/8" overhang there.....

I think it's a typo....I think she meant 24", not 34".

Yes sorry! 24" I meant.