Of course that screenshot changes the moment you switch back to that Chrome instance (tab) and begin using it ... as most of that paged out virtual memory is reloaded into RAM.
In contrast, the virtual memory manager will automatically page out seldom referenced pages of memory as needed. It keeps track of what pages of memory are referenced, and tries to keep your RAM full of stuff that is referenced often, and pages out stuff not referenced if RAM is needed for something else (or for use as the disk/file cache.. which is what your 'free' RAM is used for).
For a thorough and in-depth analysis of this type of operation (clearing the working set of all processes), the penalties involved, and potential (unlikely) benefits in some situations, you can read this page:
http://bitsum.com/winmemboost.htm ..
There are a gazillion other tools to do this too.. I even threw it in
Process Lasso as an always free feature (to periodically trim virtual memory, or trim on demand, or on trigger), because so many people wanted it, despite my hesitance to add such a feature.
I believe
CleanMem is the most popular these days.
As for trimming all active process memory every 15
seconds ... WELL, if that makes you feel better, whatever works, BUT I'm glad you didn't default to that

. That would
force continual hard page faults (a page fault is when memory is paged in from the page file because it is not already in RAM, not a crash .. though, yes, there are some types of crashes also called page faults).