Here's what something like that looks like - it tends to be easier if you have made the base object to be a little bit extended in the area that it is going to be sliced off instead of something like trying to make a wavy cut that barely touches the end of the base block at multiple points along the wave, that will make for a much more complex intersection calculation and probably a lot of little fragmented pieces involved instead of just 2 pieces for each cut.
But the basic process here is just have your base block and 2 cutting profiles, and run boolean difference 2 times using each curve as the cutting object, after it is cut delete the piece you don't want:
