
So I'd guess that it's almost totally flat at the front of the plateau, and then further back, you have hills starting small and getting bigger and bigger (until you eventually reach the mountains themselves). However, as you say, it's a big area, so from the position of the 'camera' there, you'd probably not be able to see the closest hills (too flat) or the furthest hills (too far back)... and only the tops of some of the medium-sized hills in this upland. Then possibly the peaks of the mountains behind them. You certainly won't be able to see the fields of crops from that viewpoint.
But when SRD says that they're protected by sheer cliffs on the east and south, to my mind, he's meaning that they're at the top of the sheer cliffs from which Revelstone is carved... so, yes, you can be surrounded by cliffs on the plateau- they drop right down from it.
Although Revelstone, without a doubt, faces east. Maybe slightly south-east... but yeah. You can see on the map in the books that the mountains are to the west, and at the start of Gilden-Fire, Korik and the others wheel their Ranyhyn around (after seeing Elena's signal) and "went running into the east". Plus, in I think LFB, Covenant looks out of the tower and sees the late-afternoon shadow of Revelstone cast over the plains in front of him.