Often a Monday or Tuesday can be a bit slow at the local bars.
At my own favorite Cafe 080 in Noord it can also happen. http://www.cafe080.com/
The bars basic clientele is Dutch and other Europeans that live and work on the island, so you will often see your favorite bartender or waiter from the resorts go here after work, especially Friday night is full speed.
But a "slow" Monday night can expand your cultural horizon, at least that is what happened to me last week. There was a bunch of Americans there and the staff suddenly produced their new "attraction" which was completely unknown to me and to the Dutch people there, but all the Americans jumped on top of each other to get to it and knew all the rules and tricks.
It is basically a table where a bunch of plastic cups are raked up filled with beer at each end. Each team (at each end) then have to throw a table tennis ball in one of the other teams cups and the other team then have to drink that beer.
It is called Beer Pong and it seems that every American have played it during College. (And I brought all ages back to the college years it seems .
They got into it like crazy and it was quite fun to watch and looked even more fun to play.
So another piece of American culture on Aruba , but it really lived up a Monday evening.
(Seems like there is even a professional World series in it http://www.youtube.com/watch?v=JOYduGqZSRc ).
So if you are bored or want to go back in time to your college days, you can just ask the staff to setup the Beer Pong.