Unfortunately no, slate is a layered rock and must be split at a flat layer to get a flat face. This is commonly done, but I wouldn't know anyone that would recommend going at your floor with a chisel to try and remove those layer bumps...you'd just make the floor thinner and end up with what you started with or worse.
- Short of replacing the floor, the only idea that comes to mind is to build-up the low-spots with lots of polyurethane or a clear epoxy. Basically, pour it on and mop it around until everything's smooth, flat and level and let dry. Then that, could be sanded to perfection. See what a wood or tile flooring person or company says about that or your situation at all.