I have a big beautiful cut of a tree for top of table

Hey Lillie, on this website gives you some different ideas that you can look at maybe you can find one that you actually like .

https://www.pinterest.com/njenn1/wood-slab-ideas/

Maybe look for the forked branches of some old dead trees, like maple, that can be peeled and varnished with the ends fitted into drilled holes under the table top? I am picturing what they call twig furniture.

Someone recently posted a sliced wood table she made using metal toilet brush holders as legs. It was stunning. It was on H/T a few days ago. I remember she used some sort of bolt to hold the legs on.

There are some wonderful pre-made legs available at some of the home stores. I am not sure how heavy a slab it is but the metal hairpin styles legs are popular. Not necessarily "cheap" but they look really nice.

Ready made legs are available at lumbar stores. Just stain to match. Then install. Also you could pick up a table at a thrift store inexpensively. Remove the top and use the base.

check google or Amazon for table legs.

Hairpin legs are really popular with raw wood.