What is written in front of Hashem?
Rashi: Their sins; their verdict was already decreed and sealed.
Radak: The great sin. It is not erased. It is written in front of Me to remember it always.
Malbim: This is unlike one who writes in order to remember for a long time. Here the writing is in order that I will not be silent until I pay.
What will Hashem pay?
Radak: The evil of their fathers that joins with their sins in Galus; the former is primary.
Why does it add "v'Shilamti Al Cheikam"?
Radak: Even though in the future I will bestow 'payment' to their children after them, now I will pay them themselves who did the evil.
Malbim: The punishment will not be to their children, rather, to them themselves.
