Let me first off by saying I have booked with CruisesOnly for the last 25 years. I have never had an issue with their bookings for me. Understand that CruisesOnly can only "REQUEST" a time and dining table for you be it a couple cruising or a group. The final decision is purely up to the cruise line. On past cruises, I had requested a table for two when I booked with C.O. only to have them change to a large table by the cruise line.  It may have to do with the cruise line but on my upcoming cruise, I have spoken to Princess directly to make changes from a table for two to a table for eight and even though I had booked through an agent (CruisesOnly), they had no problem in making changes for me.