Monuments and reliefs are easy to make with spare miniatures or their parts
I think the pictures explain the idea how to make this thing:
1. Build the basic shape of the tomb from a stiff card stock
2. Glue some bits, especially spare shields, to its sides
3. Paint the whole thing (black undercoat then grey drybrush)
4. The epitaph was typed on a computer and then printed and varnished