We've never had a balcony on Carnival, but we were on Grand Princess (Caribe Deck 310) and our balcony had two chairs and a small table. It wasn't very big, but big enough for two!
I'm sure you know the brochure's photographers use wide angle lenses! They also show all the passengers as young, tan, beautiful and in formal attire
! I don't think any "regular" balcony would have room for four chairs and a table.