We are considering an overnight flight home from ATH next spring with an 18 hour overnight layover at MUC. Prefer not to stay at airport but going all the way into Munich (a place we have visited recently) may be too much. Is there a town nearby that we can get to easily that would have decent choices for dinner (Sunday night) and nice walks to stretch our legs before our 1:00 PM flight back to CLT? Thanks in advance.

Freising maybe?

Having said that, I'd probably just stay in Munich, it's only a 45 minute train ride from the airport to the Hauptbahnhof.

Munich Ost is also an option, straight shot to the airport. We've done that a few times.