Saving and Loading many objects

Hello, I am making a rhythm game and am working on the charting engine. The charting engine uses a “page” system where you click an arrow and it increases a variable called CurrPage and deletes all the current notes on the chart. How would I make it so when the page turns the last page of charting saves and the next page of charting is loaded and so on. I can provide my very barebones project for you to mess with.

Here’s an example using trees. It might help.