Convivially means “in that friendly, cheerfully social way.” People chat convivially; they gather convivially around a table. Like convivial, it sounds a little formal or bookish, the kind of word a writer chooses when “happily” is too thin and “wildly” is too much. In ordinary speech, most people would say “in a friendly way” or “cheerfully together.” It describes manner, not place: you do something convivially. It does not mean “conveniently,” even though the two words look a little alike at speed.