This is one of those questions that really doesn’t need me to answer. Each group will know what they want to do. My group, for example, likes to have some kind of snack as one member comes from playing tennis, another from work and we meet at dinner time. So, we take turns providing what we think of as a light dinner, and we don’t mind eating while we talk so that the evening does not go too late.
A group I belonged to years ago had a full dinner before we began discussing our work.
This was a great way to socialize, but as I had young children at the time, I often had to
skip that first hour.
If your group is large, it may not be a great idea to encourage meals as part of the meeting as it becomes too much work. But drinks, yes and bowls of peanuts, yes.
Making stories about food as a prompt is also fun. If anyone in the group is feeling stuck for ideas, perhaps suggest that everyone bring something that reminds them of a past event. This is great for groups concentrating on memoir, but also for the practice of writing descriptive paragraphs.
There is no right or wrong answer. Food is fun.