Final answer:
Macbeth decides to carry out Duncan's assassination quickly, suggesting that too much talk can result in hesitation and inaction, thereby emphasizing the need for decisiveness.
Step-by-step explanation:
At the end of his soliloquy, Macbeth expresses the concern that too much talk may lead to second-guessing and lost opportunities. He concludes that if he is going to assassinate Duncan, it would be best to do it swiftly. More than the act itself, Macbeth is worried about the consequences and the moral implications of regicide.
Ultimately, he decides that action is preferable to deliberation, implying that overthinking can lead to paralysis by analysis. This critical decision is the driving force that leads to the tragic events that follow in the play.