Traditions vary regionally and by faith/ethnicity in most cases. I was a bit taken aback a few years ago when I was told by an older relative of DH, who lives in Colorado, that it is apparently still relatively common there to have wakes (what many call "visitation") at home. In my experience, in those communities that do wakes, that custom has mostly gone far by the wayside, and the wake will be at a funeral home, or if that's not feasible, in a shortened format at the Church, preceding the funeral service. I've been to many services where the coffin was lowered during the service; but I think that local ordinances have begun to prohibit it in some places because it is considered hazardous if a guest goes too close and slips in (I have also seen that happen. Rather hilariously in one case where a Non-Catholic mourner surprised the priest with an attempted embrace. He was startled and stepped back, and ended up falling into the grave. That is one funeral that everyone who was present remembers VERY well.)
IME, funeral homes are 24/7 businesses, because I've always lived in places with Irish Catholic or Jewish traditions, and in those faiths it is traditional to have a family member stay with the deceased at all times before burial. (Normally for preparation these days, in the same building, but not in the same room until after the deceased is placed into the coffin.) Since the pre-burial rites take a full day or even nearly two, that means that the family comes in shifts and takes turns sitting overnight. Until recently cremation was rare in my community, but that is changing quickly; the last full burial service I went to was my mother's, 18 years ago.
I have never been to a funeral that had an actual lunch served afterward; it is normally very generous hors d'oeuvre type fare, eaten standing while chatting with others who are paying their respects to the family, and only the elderly will be seated for it.
