Been looking at this big old chain sawed 16 x 18 slab for quite a while (few years+) now.  Just got a set of Slab Dawg's in so decided to see if they work holding odd shaped pieces down.  Appears that they do.  I believe this might be walnut.  It's heavy and hard.  Doesn't need much, if any, touching  up.  Was going to just put a couple coats of poly on it unless there's some better ideas.

I might consider an oiled look. I would probably finish it with a couple of very light coats of tried and true 

Any oil will darken in considerably.  It benefits now from shadows helping reveal the 3D shape.  Darker and much of that will get lost.  A water based poly or any good clear lacquer will keep it lighter than any oil based finish.  I fear though with any water base that the grain may rise, so a sanding sealer (conditioner) first. 

4D