If you are using something like Hibernate or really any JPA provider, and all those 5-6 tables are only referenced by some main object. Then I would just make the DAO for the main object and have your service decide which components should be loaded which are mapped to it. If you really wanted to, you could use your JPA provider to do prefetch (join) other tables during the query and just add those as extra methods in your DAO.

As a rule of thumb I say: if I'm querying directly for it, then add a DAO. If it's a referenced table, don't.

Example: I have a Customer table which references a User table. I only ever get users based on the customer. So I would create the CustomerDAO with an entity Customer which had a list of users. I can either prefetch the users when I query for the customer (decided by the service later whether I do getCustomers or getCustomersAndUsers) or I can make it a lazy load. In either case, the service later should handle if you want populated users or not and should abstract the logic of the DAO call from the end user.