This is a table with Card 1 along the top and Card 2 top to bottom on the left. When you are dealt a particular hand, you can make notes in the appropriate box. Does anyone do this?
I use my phone for taking notes as most people are used to seeing other players on their phones. It doesn't get other players suspicious about you taking notes. It just looks like you're distracted and texting. Most rooms do not allow you to use your phone at the table, so I just lean back after the hand is over and make my notes.
And kudos for taking notes, but you should probably just notate hands where you find something interesting or were confused about what you should do in a particular situation. Too much note taking and you will actually end up getting distracted.