Each vertical row is basically a page by doing so. Correct? This would also mean I could use the array.X as the variable to set the page navigation right?
Exactly :)
What I don't fully understand is why you subtract 1 from the 0-based X? Set at XY. X = array.width-1?
When X is set to 0, it basically means the width of the array is 0, as in 0 fields. As it shows in your screenshot, Elements: 0. The moment you push your first note, your array becomes width 1. So right after when you want to set the type/content, you need to access the 0th field and you need to subtract 1 from width to get the last field that was added.
In other words, an array with a width of 3 has three elements that you can access with X=0, X=1, X=2. An array with width 1 has one element that is X=0. And an array with width 0 has no elements to access.