The churchyard at Himley is a microcosm of the history of graveyards. Though it is comparatively small, it has a long history of burials, and a number of different types.
The small, half-sunken marker stones you see in the photo above date back to when the idea of commemorating an individual started, the 17th Century (before then, one was buried, yes, but there would have been no marker. In a sense, it was the start of Individualism!)
Himley's more modern smaller graves were presumably for the workers who toiled away on the grand estate nearby.