Cocktail hour isn't necessarily a "break time' but it is similar to saying "happy hour" now. It just tells us it is drinking time! :)
--- Does it mean that he's telling people about both good and bad times when he played in Vegas?
You are correct. It sounds like he's simply telling old stories--all of them, good, bad, and everything in between.. It is phrased in a somewhat unexpected way, because the common phrase is "the good old days," so this is an anti-cliche and the writer is having a little fun with the language and what we expect.
Student or Learner