The quote you refer to is said by Puck to the Fairy that he meets while wondering through the woods, and is very interesting in the way that it reveals his character to be one who loves causing mischief and playing pranks. Consider the quote in its entirety and what is shows about Puck's character:
Then slip I from her bum, down topples she,
And 'tailor' cries, and falls into a cough;
And then the whole quire hold their hips and laugh,
And waxen in their mirth and neeze and swear
A merrier hour was never wasted there.
But, room, fairy! here comes Oberon.
It is important to be aware of the very visual nature of this speech. What do you think Puck would be doing when he says this speech? How would he be acting out the scene and the reaction of those watching the "old dame" who is tricked into sitting on a non-existent stool? Devices such as onomatopoeia in "neeze" and the very suggestive words that describe physical movement clearly indicate that the overall effect of this speech is to present Puck as a character who is in love with causing mischief and delights in tricking other people.