Notice that in the View Options you first see the name of the folder you're working in. Standard means you are currently seeing your default view stuff. Minimizing your default List View may speed up your Mac. Custom means you've made changes. With List Views less is more.
Fewer columns equal more speed.
For every column of information you request from the Finder, the Finder has to do more work. It's a nice perspective. Calculate folder sizes calculates and reports the size of the folder by tallying up all the stuff inside it. This can take some time. If you need to see several folder's sizes you may want to turn it on, then turn it off later.