About a hundred years ago when I was young, this was simply how it was "done" in rural areas: The churchwomen brought covered dishes for any church event be it wedding, funeral, or Sunday School picnic. You provide the punch and the wedding cake. This differed from the urban traditional "reception" in that farm families generally have to travel miles to come to anything, so sending them home unfed would be as unthinkable as expecting one family to provide a hearty meal for the whole community.
The urban version was to follow the wedding with "finger-food": petit fours, cucumber sandwiches, tarts, hors d'ouvres, all set out on trays around the church hall; with your mother and mother-in-law pouring tea while the guests all circulate. This is, in fact, what a "reception" is; the modern post-wedding hotel dance-party has borrowed the term for something relatively modern and quite different. You don't serve a full meal because in general people don't have far to go home. You provide the finger-food, punch, and wedding cake (and even champagne if you want to) and you can still have speeches if you like.
And, among many traditional middle-class Canadian families of an English heritage, that's still the standard and large wedding dances are considered vulgar.
