Here's the top of my top:
Code:
CPU states: 0.8% user, 0.0% nice, 0.0% system, 0.8% interrupt, 98.5% idle
Mem: 216M Active, 476M Inact, 256M Wired, 25M Cache, 111M Buf, 8320K Free
Swap: 2019M Total, 33M Used, 1986M Free, 1% Inuse
So I think what we're seeing here is fairly standard. I think it's just the way FreeBSD allocates memory. Note that while I only have ~8MB Free, I have 476MB Inactive. Look at yours, it's something similar too.