Executor-class Super Star Destroyers can also carry some 38,000 ground troops, bumping up the human complement somewhat, but there's still lots of space for activities. Star Wars field guides are fuzzy on exactly what you'll find on the ship.
Darth Vader's flagship is about 57 times the size of a US Nimitz-class carrier, but only needs around ten times the number of crew members. A more accurate comparison might be a modern-day aircraft carrier, but even there, the Executor seems understaffed. Manhattan itself has around 1.6 million people, down from 2.3 million in 1910, while the Executor only runs with 50,000 souls. But while the ship is big enough to squash much of the city, it boasts a surprisingly small population for an area so large. The picture provided shows the Executor stretching most of the length of Manhattan. Fortunately, Redditor movielover278 is on hand to help out, transposing the vast vessel from the space around the forest moon of Endor down to the surface of Earth. While we see the former crash into the latter in Return of the Jedi, it's tough to tell exactly how big the ship - taken by Darth Vader as his personal flagship - was in real terms.
The Super Star Destroyer Executor was, after the Death Star, Star Wars' second-biggest beast.