Hamlet's decision to kill Claudius had to be a hard one for him. Even though Claudius killed his father, that is still his uncle and he is family no matter what. I agree with Hamlet's decision to wait until Claudius is in a sinful moment to then kill him. Claudius does not deserve to get the easy way out and go straight to heaven when he dies. If King Hamlet did not get time to pray before he was killed, then Claudius should not have that benefit either. If Claudius can be disloyal to his own family then I think that Hamlet has the right too, he should just give it more time.
This scene shows that Claudius does feel guilty about killing his brother. Even though he did not have the courage to tell Gertrude about the murder, he still was able to open up to God and ask for forgiveness. Maybe he was going to eventually tell Gertrude the truth? Maybe he went to God so that he finally got it off his chest to someone? Maybe he thinks that he will actually be forgiven for his murder. It also shows that Hamlet is the type of person to think something through before he takes action. Rethinking something before you act upon it can save you from a lot of regret. Since so many people think that Hamlet is going mad, I can only imagine what they would think about him if they found out he had killed his uncle. That would be two kings dead and Hamlet is the only one left to blame. The people may even think that he is after the throne and that he is responsible for his fathers and uncles murders. They will all go against Hamlet.