I don't think anything is suspicious, but if you don't like the fire, just ask him nicely to stop. Don't see how any one would find that rude, if you ask nicely.
Tables turned on their side blocking a fire being burned on concrete isn't suspicious? Plus I'd first need to figure out who "him" is before I could ask him nicely to stop. Pretty sure like 10 other guys live there. Or at least they have a lot come and go.