You will not have an issue. Viking withholds 50-60 % of the tables at the specialty restaurants for booking on the ship. So on the day you board, immediately check availability and make the reservations you wish at Manfredi's and/or Chef's Table. Plus, then you will know what menu is on what day at CT, as well as have a better idea of your personal schedules. I would, however, not wait beyond the first few hours of being on board, as many of the veteran Viking Cruisers I know, including us, use this strategy.