A Microsoft file hosting and synchronization service.
Hi everyone. I came across this thread searching for a solution to the same problem.
Brief summary of my case: MacBook Pro 15" 2014; long time OneDrive user without any problems (actually, a big fan, once I got over the trauma of renaming all my files to avoid the space, " ", at the end of filenames); previous OS was Sierra; updated OS to Catalina and the fan and battery-life went into meltdown. Similar numbers in the activity monitor as reported by the OP.
After reading some of the comments, turned off the 'Files On-Demand" setting in preferences, and low and behold the fan has taken a Valium and tranquility reigns again. I don't remember having this stupid feature under Sierra and I certainly don't need it. Only half hour into the new setting, so will report back if any of this changes.
TLDR: solution for me was to disable 'Files On-Demand' under preferences.