...Unless your running a computer which struggles to run Half Life on low, I doubt how that's a problem. 450 kb of memory isn't even half of a megabyte, and most modern computers have a RAM between 1000-2000 MB, which is 1-2 GB's of RAM.
Anyways, if you want the usage of memory to go down, delete the plugin.
Sorry, I meant 450 000 kb, 450 Mb, sorry about that