It depends on what direction you're going with the delay. If you focus on Hamlet's intellect and how his philosophical pondering delays carrying out his revenge, your title could play on this. For instance, for the audience to get the development of Hamlet's character and his thought process, it was necessary for Hamlet to have a relatively large number of soliloquies. So, maybe go with something like “Too Many Soliloquies.”
Hamlet considers existence (“to be or not to be”) in an unjust world, and he considers the moral, strategic, and dramatic implications of how he will carry out the assassination. So, he considers and reconsiders how to "perform the act" (killing the king). He delays “acting.” This is one of the fascinating aspects of this play and one of the reasons it has been studied so much. So, “to act or not to act or . . . how should I perform this action” is another “play” on this idea of delaying action. There are just so many puns you could use that deal with Hamlet's delay: play, act, perform, plot. “Lights, camera . . . hold on let's think about this some more” is a pun more appropriate for a film adaptation, but Hamlet is really "setting the stage" and then delaying the action.
Whichever direction (another pun of theater jargon) you go, Hamlet's development is eventually self-induced: a purposeful, albeit delayed construction. Hamlet does begin grief-stricken, but then develops his madness out of grief and strategy. He writes himself and literally rewrites some of the play within a play, so we have to wait while he's sort of writing some of the larger play as he goes along. And with the play within the play, Hamlet is purposefully increasing the drama. In other words, when Hamlet talks to the players, he asks to "rewrite" some of the play. He's rewriting lines!
In Act 3, Scene 2, Hamlet is telling the player how to act in order to appear "natural."
Be not too tame, neither; but let your own discretion be your tutor. Suit the action to the word, the word to the action, with this special observance: that you o'erstep not the modesty of nature. For anything so overdone is from the purpose of playing, (III.iii.15-19).
This is something to think about in terms of his delay. Although it is the play within the play, this is like the director or Shakespeare himself interrupting a live performance in order to tell the players to "act natural." This is the advice Hamlet gives to the players and it is something he struggles with himself: how to act, to be and to do.