I can't tell by the picture, but it looks like cherry inlays in a maple table...am I right? Here are a few things I notice. I am not sure of the difference in expansion/contraction factor of cherry vs maple (or whatever the woods are). If the two woods expand/contract at different rates, that will cause bowing. Next, from the picture I see that the growth rings on the ends of the boards are all curving the same direction. That will also cause excessive bowing. You should flip/flop every other board so the growth rings oppose each other every other board. This will cancel out bowing all in one direction. The way you store that glued up panel will affect the bowing. If you lay it flat on a table, the exposed side will either expand or contract at a different rate than the under side due to humidity differences on the table surface vs. the air/room humidity.
I have seen all of these things happen at different times. Depending on how you attach the top to the frame, you may eliminate the problem or see the top tear loose from the screws. Make sure you finish the top and bottom sides with equal amounts of finish coats. If you only seal the under side, you create more problems that can cause bowing.