I've heard of lachsfisch (sp?) in German for salmon, and I think the Swedish term is similar, so if I ever heard the term, I probably attributed it to German. I've certainly had a lot of smoked salmon spread and smoked salmon by itself, I've just don't recall ever hearing it referred to in English as anything other than "smoked salmon".
So yeah, I recognize that word as German or Swedish, not English.
Nova Lox and Schmear (yiddish for smear/spread which is usually cream cheese or flavored cream cheese)on the menu.
I'd say both terms(lox(originally pronounced lacks) and shmear) are sufficiently commercialized that they are common at any bagel place even outside of cities with large Jewish populations.
At least in the US, maybe not in the UK.
Also note that most lox isn't actually lox.
Traditional Jewish Lox is brined salmon belly. These days lox usually refers to any smoked salmon, especially less salty types then traditional lox