Party participation

I just got one notice a letter/some news from my cousin, he said his colleague sent him an email about a family party to him. He wants to organize some families to go on a picnic in Metropark in this Saturday, but (so far) he is alone. I want to say that he received the task of preparng snacks for over 30 participants, i don't understand why they gave this mission to him, because we almost never eat snacks in our daily life. For Chinese men, it is do difficult to prepare the snacks for so many people. First, we don't know what should be prepared for this kind of party, especially since/because most of his colleagues are from India and don't eat meat, so we have to consider this (or: take this into consideration). Second, we don't know how many snacks is the right amounts. OVER 30 PEOPLE, these really is troublesome for us, maybe it is very expensive or it is very thankless.....i hate this mission (task)!!

Besides, every family should bring 1 dish on the party day. Becuase my cousin has already been given that task, so he needn't (in the US: doesn't need to) prepare anything else. I heard the organizer's task is to prepare the water......such an easy task! I have to say, preparing snacks is the hardest of all tasks, why don't those families don't (help) shoulder or share the burden? Or they could bring their favourite (in the US: favorite) food to party, it would maybe be the best way for this type of party. And honestly, in this reason, a grill is ok outside/outdoors. If they only bring the cold food to the picnic, i won't like it very much, but they almost don't have any (better: they have almost no) animal products whatsoever.