Windows and certain programs will create system restore points automatically. Unless you have a shortage of space, this isn't something to worry about. You might find these system restore points very useful should the need arise. If you have disk space issues, then you can limit the amount of space system restore will use. This will of course limit the number of available restore points, with the oldest being deleted when a new one is created.
When you delete the restore points, it does just that, takes those files and deletes them from your PC. That particular restore point will no longer be available. Don't worry over the extra space used, since you have plenty of free space at this time.
System restore point deletion does not affect the hibernation file (Hyberfil.sys). But yes, if you have hibernation option turned on, the hibernation file can grow quite large. Again, don't worry about it if you want to use the hibernate feature, as you have plenty of space. If you don't use hibernate, you can turn hibernate feature off. Hibernate - Enable or Disable
It's good to learn what your PC is doing, but as I say, unless you are running low on space, don't worry about it, as you know why these files exist.