Didn't see anything like that in any of the lounges but, if I remember correctly, there were wings and ribs and such on the buffet line from time to time. There is a 24 hr pizza and calzone station that was pretty good and hamburgers, hot dogs, and fries were served every day on the lido deck till around 5:00. You're going to be amazed at the amount of time you will spend eating and the amount of food you will consume. I gained almost 5 lbs in one week. Have a great time!
This will be my first Carnival cruise. However, on Holland America they served hot finger foods (very yummy!) a couple of hours before dinner, but not all day/night. Kind of like a happy hour type thing. I wouldn't have known if the art auction hadn't run over the normal time since I was usually taking a little rest before dinner or getting ready for dinner. You might try with Carnival during those times or ask the bartender if there is a certain time they offer snacks.