I'm almost in the same boat! I'm trying to figure out what to do with my chestnuts.
I'm usually simple with walnuts, and I eat them as a snack, plain. But then again, I'm the same with chestnuts (roasted chestnuts). But haha, it's not that simple when there are so many.
The first thing that came to my mind, is a nut filling for kolacky (kolaczki?) cookies. It's my second favorite christmas cookie!
https://www.tasteofhome.com/recipes/hungarian-walnut-cookiesI'd check out similar recipes too, in case one seems easier/better for you.
Another thing I've thought of is a nut roll. This isn't anything that I'm familiar with making, but I've gotten it at bakeries before.
https://www.tasteofhome.com/recipes/hungarian-nut-rollsI personally would attempt a nut butter if I had that many walnuts.
That stuff is expensive. I've never tried walnut nutbutter, but I've tried a few other nuts (cashew, almond, pecan...)