The files and folders you see within the Temporary ASP.NET Files
are normal, they are the result of the ASP.NET compilation process which occurs on web application startup.
You can remove unused files and folders using the following PowerShell command, it may be worth recycling your websites application pool before doing so (to ensure your websites files are not locked):
Get-ChildItem "C:\Windows\Microsoft.NET\Framework*\v*\Temporary ASP.NET Files" -Recurse | Remove-Item -Recurse -Force