Idle "mini-surge"

I've read a number of posts about engines surging a significant number of RPMs but my case it's less severe. I'm revving between about 700 and 800 PRMs, so little in fact that it's hard to see the tach move. Is it likely to be the same issue? It doesn't threaten to stall or anything, it just sounds like I'm tapping my toe on the gas about once a second.

Thanks
Dave