As someone to new to Mac, I did miss the PageUp, PageDown keys. I just found that you could use the arrows keys in combination with fn key.
fn + Up Arrow for Page Up
fn + Down Arrow for Page down
fn + Left Arrow for top of the file
fn + Right Arrow for bottom of the file
I am not sure why I haven’t searched for the solution earlier. Perhaps I am content with the navigation keys in vi/less.
G – bottom of the file
g – start of the file