No. "מסעדה" is a feminine word and therefore you need to use "זאת" or "זו", and also the word "את" should not be used here.
Why EIZE MA'IL ZE was accepted as the right choice for "What is this coat?" but when I tried "What is this restaurant?" for EIZO MIS'ADA ZOT, it was rejected. If this answer is wrong, the previous one should also be wrong.