Raymond brought home a suitcase but wanted his wife to put it upstairs. At some point the suitcase got relocated to the landing halfway up the steps. To teach Ray a lesson, his wife put a big wheel of cheese in the suitcase (presumably stinky cheese). She tells her mother in law what she has done and Marie tells a long story about a grudge fight over a big ugly fork her husband nailed to the kitchen wall. So Marie bought a big spoon, just as ugly, and hung it just a little bit higher on the wall. The fight over the big fork and spoon had been going on since they were first married. Marie was warning Ray's wife not to let a suitcase full of cheese become a long-standing fight like the fork and spoon were. But, having been married 38 years myself, I assure you that if it isn't a big fork and spoon or a suitcase full of cheese, it'll end up being something moronic (in my case a potato peeler) that becomes a catch phrase hair trigger argument.
My wife is a fan of the show and heaven forfend that I should change the channel while it's on, so I've seen every episode about a thousand times. Fortunately, it's not a bad show, well written and often funny on many different levels. Sometimes it's even subtle.