Mehmet Iyigun spent some time discussing why the System process in Windows 10 is taking a bit more memory and why it’s a good thing. The OS is doing some clever optimizations that allow your processes to trim some of the memory but not necessarily page it out to disk. Not only is the memory preserved in RAM, but it is also compressed – making hard page faults a more rare occurrence. The results should make for a snappier experience. This feature is not an experimental feature: it has been available since the RTM bits of Windows 10 were released.”]
Source: https://channel9.msdn.com/Blogs/Seth-Juarez/Memory-Compression-in-Windows-10-RTM