New
#1
Do you have a ton of tabs open? Have you tried closing Chrome entirely? Does the problem return if you do?
Are you having an actual performance problem, or are you just disappointed when you see that much RAM in use on your machine?
Windows will free up RAM as it's needed for actively running applications. I'm of the opinion that if I have 8GB of RAM, I want nearly 8GB of RAM in use. RAM is faster than my hard drive.
If you don't use your RAM, what's the point of having it? It's like buying a 2,300 square foot house and choosing to only occupy 800 square feet of it, so that you have plenty of space available if you ever need it.