Drying and sanding cherry tree disc for coffee table
I think it all depends on what you're trying to achieve in a final look... 

If you need the top to be perfectly smooth (no cracks, no blemishes), there are ways to do that, but they involve some fairly serious woodworking tools and time. 

If you're willing to go a little more rustic and accept the wabi-sabi of it all, then get a belt sander and flatten the top; apply linseed oil; get some legs on (preferably 3 rather than 4, with a slight degree of adjustability); and let the natural checking process begin.