Windows will keep unused code in ram in anticipation of eventual reuse.
I am guessing that compressed means that some code is compressed to save space.
Retrieving code from ram is much faster than from an external device.
I suppose that uncompressing is a small price to pay if more can be stored.
What bothers me a bit is that this is there after a boot.
If you are using fast boot, I think previous contents of ram are retrieved upon booting, likely from the page file.
The key to determining if you really have a problem is the hard fault page rate.
That is when windows needs to swap out some overcommitted ram and retrieve what it needs from the external page file.
If you see something more than one per second, I would look into this more.