If its solid wood then a belt sander and some finer grit paper is fine, but still have to be very careful and keep the sander moving all the time. If it is veneered then a belt sander is a very bad idea, too easy to completely go through the veneer at the edges and then the table is ruined.
If it is veneered then a cabinet scraper and a lot of patience to remove the finish, then 180-240g sandpaper to finish is what I would use. If it's chipboard with a photo of wood glued on top then it's new table time
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