Table top/plaque

Another indoor blip as the weather is so foul!
This, again, is an inherited piece. I think it was originally a table top as it is about 3ft across. When it arrived in our household the wooden frame base was missing and I could only think of putting it on the wall. It is extremely heavy and is hung very low down in a convenient alcove - underneath the toby jugs,. (This was just as well because one day it fell off and could have done a lot of damage had it been hung higher!)