I would like to add game (as in: dead birds, dead hares, etc) as a frequent subject, suggesting prosperity for the table, but, to another level of reading, the ultimate common destination.

All that is "multiple" is a symbol of abundance, that's why, in my country at least, sheeps, spiders, grapes, lentils, pomegranates "bring good luck". One often find this "multiple" objects, especially a pomegranate or and bunch of grapes, to express wealth. A few tarnishing, shrinking grape etc detached from the bunch might, again, subtly suggest how easily richness is lost.

The idea behind a Vanitas has probably changed: we nowadays see it as a carpe diem statement: enjoy life while it lasts. I suppose in the mind of the authors of centuries past there was more of a religious meaning: remember you have to die, and be judged! You cannot escape death, so behave!

This changes the perception of the owner radically: if you were a Dutch merchant exhibiting a Vanitas, or a Memento mori (which I think is more specifically referred to an open reference to death, with a skull etc.) you didn't do this to show an "epicurean" message about yourself but, on the contrary, a "religious" message: you are rich but you don't forget thinking about your soul.

As a side note, they say crows are considered to bring "bad luck" by the ancient Romans (and so by us modern westerners) because they appear to say "cras", short in Latin for "hodie mihi, cras tibi", typical inscription on Roman tombs: (it happened) to me today, (it will happen) to you tomorrow, a writing often associated to skulls, skeletons etc also in modern illustrations.

http://www.alamy.com/thumbs/6/%7B062...%7D/BBTCXJ.jpg