Hello Basil :)
You should not hide these updates, and should continue to download them. Firstly, the fact that you are being offered them at all means that you have do have .net installed. If you hide these updates, you will not get patches for various security vulnerabilities, so you will not be protected. Hiding them only makes your computer vulnerable.
So the next question is do you need .net? Because surely you could uninstall it, and the updates wouldn't come through. Well, yes and no.
If you did uninstall it, the updates wouldn't be offered. But I would strongly advise against it. There are two parts to .net (arguably three, but let's not get bogged down in technicalities), the part for developers, and the part for normal users. You currently only have the much smaller part for normal users. Developers need a much bigger download. If you remove .net, you will suddenly not be able to use any application created with .net. This is bad, so I would advise very strongly against removing it. :)
Some small parts of .net are so built into the OS that they cannot fully be uninstalled. But even so, you will happily manage to break a lot of apps if you forced an uninstall.
I shall now predict the next question
I have many versions of .net on my system, do I need them all. The short answer? Yes, you do. They are not fully backwards compatible in the way some people expect. Some versions are backwards compatible with some other versions, but at the end of the day, if you start removing any, you are extremely likely to break some application or other.
I can provide more details if you are interested. These are just the short answers: it summarises to: don't uninstall any .net versons, and do install all updates. Otherwise .net applications will break and/or you leave your computer vulnerable.