I have attended over a dozen funerals during my lifetime of 70 years. Perhaps due to cultural or regional customs (I live in San Francisco, California), food was never served to mourners after the funeral service in the homes of relatives or friends of the deceased. Instead, relatives or friends of the deceased always host a restaurant meal for the mourners after the funeral service.
In all the funerals that I've attended, there was an average of 50 mourners. Insufficient space in people's home to accommodate an average of 50 mourners is also a consideration for relatives or friends of the decease to host a restaurant meal.