Very many processes for a single program?

The images you linked to are not showing "very many processes", but rather "very many open handles", as the window in the screenshots is for searching for open handles, and all of the "thunderbird.exe" listings show the same "PID" (Process ID) and likewise all of the "firefox.exe" listings show the same PID.

And just to be clear, it is perfectly normal for one running process to have many open handles.