This is a 8 inches x 8 inches or 21cm x 21cm ink stone. It is practical to have a bigger sized stone.
I like to grind my own ink. Drop a little bit of water (a half tea spoon) and grind in circular motion. I take it as a calming down and mental preparation time.
When I was young, my sisters put a couple of cypress leaves inside. It smell the fresh forest. In Chinese, we say it the fragance of ink. (mo xiang)