I keep asking my mom "what's with all the 'top it with mayo' crap?" and she says "they didn't have much else and it was handy!"Sigh.
My Grandma Mary was a great user of mayo...especially on woebegone Jello salads trembling with bits of celery and pineapple and green olives interspersed throughout. It's the reason why Jello molds loom so far in their legend on this blog...for my Grandma and her lime green Jello salads topped with healthy dollops of mayonnaise.