After Bob, Lucy & Ricky perform the song "Nobody Loves The Ump", Bob does a dance routine in which he says: "If Marge sees this, Howard is finished." Who were Marge & Howard? I am assuming it was an inside joke.

Also, after Bob does the routine, for whatever reason Ricky does a Cuban dance number that seems to be out of place. Waht was the point of that other than for Bob to say: "That will set Cuba back 100 years."?

I believe Bob was referring to Marge and Gower Champion. They were famous broadway dancers and coreographers.

I knew it was an inside joke. Thank you.

You're Welcome!

Marge and Gower Champion were dynamite dancers at the peak of their popularity in the 1950s. Marge Champion is still living, while Gower passed away some years ago. For a great example of their talent, check out the 1951 version of "Show Boat" in which they do two fantastic dance routines.

Also, after Bob does the routine, for whatever reason Ricky does a Cuban dance number that seems to be out of place. Waht was the point of that other than for Bob to say: "That will set Cuba back 100 years."?

He was referring to Cuba's culture or civilization and that Ricky's dancing was so bad that he just set back Cuba backwards 100 years.

It was actually an old line used by many comedians and writers back in those days and beyond to mock or tease someone about something they had done.

That will set (fill in the blank) back 100 years.

An old standard line that has since faded into obscurity.