That's actually closer to 2GB, but all points aside, how much RAM it's using doesn't always determine smoothness. your cpu has a lot to do with it also. You can also allocate more ram to RuneMate if you feel that however much it's using isn't enough.
I would advise posting your hardware specifications, also that's MB not KB Though I won't be able to comment until tomorrow, as it's late atm and I need to be up tomorrow.
2GB is not that bizarre. I think RS3/DarkScape takes about 1GB, and then whatever bot you're running on top of that.
