This is a Colorado Silver Maple Crotch platter or serving tray. The crotch is the part of the tree where two branches split off from the main trunk. The crotch can yield some amazing figure and colors as the two branches compete against each other and "split" the grain.
Most platters have a shallow curve to the center, but this platter/serving tray has a flat bottom. If you put a small dish in the middle with chips around it, the dish would stay put. You could also use this to carry a bottle of BBQ sauce out to the grill, and the bottle would stay upright.
The rim is 1-1/4" wide, and the underneath side of the rim has a small detail feature, which feels good to your fingers and helps you keep hold.