The Pun That Started a Round of Applause...

Pam remembered it!

It happened after the fight between King Arthur and the Black Knight (who loses his arms and legs in the process).

A beggar walks by, calling out, "Alms for the poor, alms for the poor."

Then he picks up the fallen arms. Arms for the poor. Wokka wokka!

In retrospect, it's not that hilarious, but the timing was right to bust out the applause.