The Japanese word for "delicious" or "tasty" is 美味しい (oishii), so if you wanted to say "This restaurant has delicious food" it's このレストランは美味しい食べ物がある (kono...
Generally speaking, after meals a Japanese person will say some form of ごちそうさまでした (gochisousama deshita) which can be translated as "Thank you for the meal", but can also mean "That...