Yes, there is a Captian's dinner on the cruise, as well as a past guest party. You should read about the dinner in capers, and get an invitation in your room for the party.
The Captain's Dinner is not what it used to be in earlier cruising days. It's no more than another dinner aboard the ship UNLESS you are a very frequent cruiser with this line. On our last cruise they even eliminated the hand shaking and picture taking with the Captain as there was an outbreak of the GI's aboard the ship.You might get invited to a Captain's cocktail party aboard the crusie.