As of late, right after boot, my Windows 8.1 (64 Bit) is using 5-6 GB RAM of the available 8 GB. I found a similar question (Windows using too much RAM, how to diagnose resource hog), which unfortunately only partly helps me. The issue I am facing is that I am failing to identify the driver that is hogging the memory.
Here is some information from my system:
What the task manager reports:
Using RamMap to get more detailed information:

So RamMap clearly shows that my drivers need more than 4GB of RAM. Using the same diagonstics described in above answer, I used poolmon for further analysis (not using the grouping by via P since my issue does not seem to be the nonpaged RAM):

So what this essentially tells me is that my most memory intense driver is using ~100MB of RAM. So this surely does not add up to 4GB.
Does anyone know what else could cause the high memory consumption?