Yes you can!
Just remember that each book needs 2 people to get a complimentary main course.
So 1 book - 2 people, 2 books - 4 people, 3 books - 6 people etc. That will give you the 2nd main course for free for every second person. Meaning 2 books and 4 people will give you 2 free main courses.
If you have 1 book and you're with 3 or 4 people you can still use your book and you'll get one main course for free.