How can I create the tables with automatic update when I input new data into the original

Hey guys. I get a problem here.

I inputted some data into a spreadsheet. Here are few columns, for examples, their name, contact number and age. I classify the students into three classes, L1, L2 and L3, according to the age. And now, I wanna create three new tables for each class. How can I create the tables with automatic update when I input new data into the original spreadsheet?

With many thank.