@janbb: Does your book group usually include food? Is it food solely provided by the monthly hostess or is it a pot luck type of gathering?
My book group meets at a library once a month. I’ve been going around 7 years. It started out no food, and then a few people would occasionally bring something small to share, like cookies or juice. Now the group has grown to about 8 or 10 regulars, and we have wine, liquor, beer, savory snacks, desserts, international foods. I’m not too big on drinking alcohol but the food is almost like a dinner after we partake of it.
What you could do for your holiday cookie exchange/book group meeting is tell everyone “I’m making holiday cookies. Feel free to bring enough to share, and I’ll have containers for everyone to take some home in.” Then you can have cellophane bags or paper boxes or whatever works, and people can eat and share if they want to, or just eat if they don’t want to take any home. No pressure for those who may not be into it.