Right click it and select Open File Location. I just want to make sure it is the location it should be in.
C:\Program Files\NVIDIA Corporation\Display
Failing that, try to end it and see what happens. I have never seen this, but software can do some strange things.
If all looks good, open the Nvidia control panel and select Desktop(menu) and remove the check next to Show Notification Tray Icon. I just tried it and nvtray.exe does go away, you will need to launch the Nvidia control panel from a shortcut, but at least you will have free memory.