The first time you read this poem, you might peek underneath your own dinner table to see "what vegetable leviathan extends beneath." The second time, though, imagination fully open, you'll catch the subtle nuances.
Around one dinner table sits a "leaf on a plate like a wing," almost weightless, until we learn what would occur should it fly away. I sense the speaker reaching for something beyond her own existence. In one moment she remains in the physical world, bringing a small fork to her lips with pieces of vinegar-coated lettuce, but in the same moment a conversation is occurring within her soul, recognizing life's fragility.