Decent sized for what?

Creative writing and roleplay? Plenty, but I try to fit it into my 16 GB VRAM as otherwise it's too slow for my liking.

Coding/complex tasks? No, that would need 128GB and upwards and it would still be awfully slow. Except you use a Mac with unified memory.

For image and video generation you'd want to fit it into GPU VRAM again, system RAM would be way too slow.