@Espiritus_Corvus Putting mayo in a salad, like tuna salad, is completely different than schmearing it on bread. To a Jew it is anyway. Thousand Island is a bazaar exception that I myself don’t partake in.
I don’t know what you are talking about when you say mustard has mayo? As far as I know mustard is mustard seed and water and then sometimes it also has beer, vinegar, wine, or some other liquid. Not fatty oil and eggs. Not that I know of anyway.
I do once in a while make a dill sauce for breaded fish sticks with mayo, but otherwise none of that other stuff you named. I 86 all of that on sandwiches and I never eat creamy dressings like ranch, but dressing on a salad is a different category than a deli sandwich anyway. Plenty of Jews like ranch dressing and tartar sauce.
I have a girlfriend who is quick to say when food is very goyisha. Bland, not toasted white sandwich bread, mayo, processed lunch meats, and American cheese. it should be meat sliced from the roast (the meat shouldn’t be a perfect circle or square from a mold) bread along the lines of rye, French, or Italian, and often no cheese. If there is cheese it’s usually something with more punch like Swiss. Classic Jewish deli meats like Pastrami I never order with cheese. Just pastrami, mustard, rye bread, and it has to be good deli mustard, none of the yellow or Dijon stuff. Half sour or sour pickle on the side.
On that one link that whole thing about marshmallows I don’t agree, except to say I never saw any of that marshmallow sweet potato pie at Thanksgiving. Marshmallows were for dessert foods like rice crispy treats and to float in hot chocolate.
I’d say Jews kind of look down on some of those foods and combinations as low quality, or lacking taste (meaning lacking a palate that knows better) but plenty of us eat at least some of it. Hypocrites. :)