I play one and then as soon as I feel confident with reads on half the table, I open up another. Once I feel confident with read/notes on at least half that table, open up one more. If a table drastically changes with players, I may close one to focus back on reads (reading is my strongest strength in poker).

Tons of notes become helpful because I'm sitting at a table where I have notes on half the players already. After a few orbits of making sure the notes are correct (making sure the tag didn't suddenly start lagging it up) I quickly open up another