It is easy to get angry with people when they talk in Church, to cast aspersions on them, to judge them for irreverence and perhaps a host of other things.
This is a temptation which should be resisted. Perhaps a priest has told them that the Church is a community and we should all greet each other and chat in the House of the Assembly. Perhaps they have had a poor education in the faith, come back to the Church with goodwill and assumed that it is the right thing to talk once Mass has finished. Perhaps they are a bit hard of hearing and so talk more loudly than seems sensible. Perhaps they're not Catholic and talk because everyone else does. There could be all sorts of reasons.
So this is a chance for penance - and therefore a partial indulgence, by the way. Here's a prayer I just made up:
Loving Lord Jesus, I would like to pray in peace and silence but I accept your will that here and now this is not possible. I offer this inconvenience in union with your sufferings. Accept my poor prayers and pour out your grace on all the good people who have been here at Mass today. Help all priests to encourage reverence in Church in a sensitive, charitable and effective way, through their preaching, their prayer and their example. Blessed be Jesus in the Most Holy Sacrament of the Altar!