Hey there Wharson!
I am Miguel Ángel, an independent advisor and also a Microsoft user just like you. I'll try to help you with your doubt today.
By what I can see, and as my mate said, those executables are legitimate. I'll try to give a detailed explanation for each:
"backgroundTaskHost.exe" is just a component required for Cortana to run, which is Windows 10 virtual assistant. It is legitimate, and it is also necessary for many Windows functions. Since it is a SYSTEM32 protected folder, it's legitimate.
SDKHelper is a component needed by Office to run updates. Something similar to Office Click to Run, OfficeC2RClient, Winword and the Integrator executable, which are all components of Office. Blocking them from accessing the internet will surely cause you issues when updating, when verifying your Office license or when using Office online services.
CompactTelRunner is a Windows service that retrieves data in order to fix issues and improve your Windows experience. Disabling it, again, may involve problems in the future when you experience an issue.
OLicenseHeartbeat is the Office service required to check your Office license, and to adapt your app to the features that you've paid for. Disabling it will involve issues with Office licensing.
WERMGR is the service that sends error information whenever your device encounters any kind of problem (either solvable or critical). Disabling it can probably make debug information not generate, and therefore troubleshooting will become difficult.
The MSI7A16.tmp located in C:\Windows\Installer\MSI7A16.tmp seems to be an installer from MSI, probably an update. If you're not installing or updating anything, you can delete that file in the location and it would be safer than keeping it there.
The maintenanceservice.exe executable is part of Mozilla Firefox, and it just helps Mozilla Firefox find updates and install these. You should not block this neither, because it helps receiving Mozilla Firefox updates, and this is crucial for security concerns.
RUNDLL32 is a CRUCIAL Windows 10 process and it's completely legitimate as it runs in WINDOWS32. It moves libraries so Windows can efficiently use them. Internet access should NOT be blocked, as it's one of the most crucial Windows processes.
The other processes belong to WindowsApps folder, which is a completely protected and shielded folder, so there is nothing to worry about. These are apps coming from Microsoft Store, mainly.
I hope it helped, and it also cleared some of your fear :)