Plug.
Cured tobacco leaves are dried, then pressed together and heated before being stored.
This one is a highly dense little brick of tobacco, comprising various strains of Virginia leaf as well as that of Burley.
A plug tobacco takes some preparation, not simply stuffing into a pipe and lighting it up. It all depends on your preference; how you prefer to smoke it and the kind of pipe you're smoking it in. I've chosen to shave off pieces, resulting in something akin to, but not quite, a broken flake. It's suggested to cut against the tobacco's grain, but some may choose to peel off thin layers from the top of the pressed brick.
Some drying-out time is usually necessary with a plug; about half an hour should do it.
Aging potential with this form of tobacco is high, and this particular plug had already developed tiny sugar crystals while being sealed in its tin.
Additional information: Plug tobacco is also a sure-fire way to turn a blade blunt.