It's Windows. Process svchost.exe by itself, represents nothing, and performs a bunch of different functions depending on how it's launched. One of his instances of them may "suddenly" to consume all CPU and gradually limit your 2-4 GB of memory (!), "calmed down" after a while, and we can only guess that Windows is doing now (maybe trivial to check for updates) and just wait for when it will suffer.
Jensen.Rosenbaum answered on July 9th 19 at 13:33
On the details tab, what process loads.
View logs of system, application, log proxy
emerson.Bechtel answered on July 9th 19 at 13:35
process explorer - view on the process than he does. enough detail is visible.