Lois makes preparations for her cousin's wedding.
Lois: Whoa! Hold on, Emeril. Dinner ware stays outside
until the reception presto change-o. Untill her cousin gets married?
presto change-o. is a set phrase used by magicians at that moment when something magic happens. Maybe the scarf changes into a rabbit. He waves his wand and says "presto-change-o".
Maybe they refer to the dinnerware being in piles, and suddenly appearing all arranged perfectly on the tables.
Thanks, AlpheccaStars!