Firstly: Preparing Food for the Family of the Deceased
It is sunnah for the neighbours of the deceased to prepare food for his family that would suffice them for a day and a night.  Hanbalis explicitly mentioned three days. This is by agreement of the four schools of jurisprudence.  The Malikis conditioned that they do not gather to wale.
Secondly: The Family of the Deceased Preparing Food for People
It is an innovation  But if there is a need for this, then there is no harm in it. It may be the case that someone came to pay their respects from a distant town, and they must allow them to stay over, in which case they will also host them accordingly. for the family of the deceased to prepare food for the people. This is the position of the Hanafis, Shafi`is, some Malikis, the choice of Ibn Taymiyyah, Ibn Baz, al-Albani, and Ibn `Uthaymin.