If needed, you can use a rubber mallet to set them ... make your life easier by removing them with a hammer and masonry chisel. Final Steps And Other Things To Consider Once your first course ...

“To remove loose paving slabs without damaging your flagstones, carefully chip away at the mortar around the paving slab with the plugging chisel and rubber mallet until the slab comes ...

They would have used a harder stone to do this and this could have been the start of using a gavel or mallet. When it was found that metal could be shaped into a chisel, a wooden mallet really ...