Flame resistant suit...check,
plenty of nachos to share...check,
beer, wine, diet cokes...check,
comfortable chair to watch the sparks fly...priceless.
Between several cruises, business trips, dinners in nice restaurants, etc., I am aware of standard tipping policies, tipping extra or extraordinary services, etc. I am also aware that many of the men and women working on the cruise ship depend upon the tips to support themselves and their families back in their home country. We once had a waiter from an Eastern European country (I forgot where) who was educated as a dentist in London, England (I believe) and still made more money on the ship than he did practicing dentistry in his Eastern European homeland. Anyway...
If you bring the baby to dinner and the baby drinks formula, eats baby food or cheerios, or even bread from the table, and the waiter isn't having to meet any of the baby's needs, then I do not believe that the waiter is automatically due a "tip" for the space the baby took - gratuities are customary for recognition of service. If the waiter (or assistant, or whomever) went above and beyond the call of duty to make it easier on the family with the baby - warmed bottles or baby food, brought out special food for the baby, cleaned up after the baby swiped cheerios onto the floor, put on a puppet show while the parents ate, etc., then sure, the waiter earned a tip.
If the same logic was applied, then the family of five sitting at the table for 6 would owe tips for 6, the family of 4 who never ate in the dining rooms would owe tips for the week even though they never used the service...