The profuse and emotional talk you had with your friends was the implicit ThankYou thing for going to their child's wedding, and giving the gift. Some desi's might consider sending a Thank-you card as a belittling of your generosity. For those who are way too deep in western norms this could be harder to swallow. In eastern weddings we can "stretch" the food, as well as seating(s) to accommodate more people. Aunties always advice to get out to the dining area as soon as possible, so that the sambar/chutney items are not diluted with spicy-salted water and rice kanjee (kanjee is added to build back the body of the thing). Late arrivals who get in the 4th seating should expect a few "chef's surprises". Western weddings with RSVP would even have an exact count on the chickens, fish, beef, and pasta divides. No extra bodies can be accommodated easily.