Perhaps I didn't really make myself clear enough. Like most people I have lots and lots of items in the startup group. I go through the list on the internet, as in your Google search, and then disable the ones I don't want.
Weeks later, after other applications have been added, I go through the whole list again to disable things I don't need - but I have to check everything that is enabled, because I can't remember what most things do, whereas if I had been able to put a note by things, I would only have to check the items without notes.
Similarly, as in the RealTek example, if I had only one item disabled, it would be easy to check. But as I have lots of items disabled, in order to find out which one applies to the sound card, I would have to recheck every single disabled item. A notes field would help save the effort of keep having to recheck on Google.