"That chick from Seinfeld" or "that dude from the Mentalist, damn didn't know he was Australian!" should be perfectly acceptable answers. Knowing their names is well beyond me, I am proud to just recognise faces.
And I remembered vaguely of who Lin-Manuel Miranda was from Curb Your Enthusiasm when Larry David made the God awful choice of putting Broadway musical crap in his show.
Mixed bag of passing fame, No Woody Allen, Lucille Ball, Humphrey Bogart, Tom Cruise, Al Pacino, Maria Callas, Michael Jordan, President Trump, FDR, Al Capone, F. Scott Fitzgerald etc. etc........some of those given will be forgotten before next year.