Is there a place to buy cooked seafood at Westwego seafood market?

Yes

There's are few places to buy cooked seafood in westwego

There are a few small seafood joints right next door and a "fancier" restaurant between the stalls and the water in the back; it looks like a house but has a big patio on the back. Otherwise, the seafood market is just a bunch of stalls with people selling their daily catch out of coolers. A lot of the crab and fish being sold was bought by fishermen off the water earlier in the day.