Help with a project

I am thinking of creating an end table on the lathe. This would involve a 20 inch diameter top on a faceplate although for 99% of the project I could use the centerpiece too. It would be 6 inches thick. Should be able to start with something that is round and centered but of course not be perfect.
The lower part would be 8 inches wide by 14 inches in length. I have not worked pieces this big on a lathe. Is this reasonable?