No doubt this has been covered somewhere, so apologies for any rep rep repetition.
At the end of the play, Hamlet is dead, Fortinbras makes his first appearance, and tells four captains to:
"Bear Hamlet like a soldier to the stage, for he was likely, had he been put on, to have proved most royally."
Putting aside the question of by what means was Hamlet's body carried by four men, it seems to me that the 'stage' being referred to is that stage upon which actors perform.
Hamlet is obviously into acting: take the Mousetrap for example - he even teaches an actor how to move his arms.
The phrase "had he been put on" puzzles the mind.
regards