Going at events wasn't an easy thing for Tom as he was forced to interact with people and actually strike up conversations to boost up his reputation for his plan. Finding things for horcruxes wasn't easy at all, and most of the things he wished to have were either gone or never found again. Luckily enough though, the event had mask so he could do things more discreetly and still obtain what he wished. He just needed to play the little dumb golden boy.