You're looking at a dissected tableland, the relatively flat upper surfaces are and old ground surface. Given that the valleys cutting through are steep sided and flat bottomed, I would guess that the primary erosive force is glacial action.

You're looking at a dissected tableland, the relatively flat upper surfaces are an old flattened (by erosion and/or sediment deposition) ground surface. Given that the valleys cutting through appear to be quite steep sided and flat bottomed, I would guess that the primary erosive force is late stage glacial action towards the end of the last ice age. The original plateau was probably flattened out by the action of earlier ice sheets at a time closer to the last glacial maximum.