That's browserd for you. browserd looks great on paper: multiple applications can use single instance of browserd for HTML rendering, saving loads and loads of memory. Applicaiton start-up times (that requires HTML rendering) are shorter, and in addition browserd puts an end to all armed conflicts on this piece of rock.

In reality, though, Browser is pretty much the only application that uses browserd. browserd is very lazy in releasing allocated memory, and that combined with the fact that browserd is always running in the background you've got yourself a daemon that ends up hogging all available memory.