Every time you connect to a system (web, or mobile app) using your Google Login you are granting the developer of that system access to your account. If you see a window something like this.
The app in question Google Analytics Windows is asking the user for permission to read their Google Analytics data. Once granted the application will have permission to read the data. (When ever they want not just when you have the app open) This is called Oauth2, it is how Google and a lot of other companies allow developers access to your private data. The main point here is that you the user must decided if you trust the developer of the application.
With the Exception of android Apps Google preforms no checks to ensure that the application you are authenticating to is not going to do anything bad with your data. You the user must decide that. Even with android Google cant control what they do in the background.
The first two you have mentioned i cant tell you what they were. The best thing you can do is just remove them. If you are actually using the application that needs the authentication it will pop up and ask you to authenticate again. Just don't auto click accept on these windows check the name. If you do figure out what the applications are i would recommend contacting the developer and telling them they need a more descriptive name then that.
As for the last one. I would guess that you either have a windows Google drive app or an android google drive app that needed to be authenticated before it could access your data. Google is very strict developers cant name their products after a google product. The last one is probably a Google Developed application and should be perfectly safe to use.
As for an answer there is really no way to determine the legitimacy of a connected app. I have been developing applications using google login for years. I can tell you as a developer that if you grant my application access to your data you give me access to your data. There is no way for you to know if i am trustworthy and not selling your data on to someone else. This is why I install very few third party apps :)
Update (Picture just for fun):
This is the setup that a developer would have to include. Note a few of the fields are optional but email is not.