Henry's mum, from my experience, the less you pay attention to this type of thing the less they are likely to continue to latch onto as what they're doing for any longer than their natural curiosity would (from me experience kids seem to have an inbuilt measure on experimenting with things and need to get it out of their system). Because what they're doing is not because of bad table manners, but purely "dropping an object from height", it is a science experiment. It is something that almost all babies will do at this age - even the baby books describe this as an age appropropriate action. So I guess, my philiosophy is to ignore it for the most part. But, a few things that I found helped during the phase: place only small amounts of food on the tray at a time, I think babies can find a whole selection of stuff a bit overwhelming. So place a piece of each flavour and replace as needed. If I do find my dd had eaten all that she wants off there and I see her starting to toss it, I will remove the food in a low-key way and offer something different if I know that she is likely still hungry. She may have just had enough of the flavours at that time, or maybe on that particular day she's not into having xx. You could set her up to drop a bunch of toys away from food time and maybe in a different room if you don't want to associate the dropping for play with eating. But I've just found that it only lasts a few months if you don't make a big deal of it.
For your pulling the cat's tail scenario - a good way to deal with this type of thing is to instead of saying "no, don't pull the cat's tail" (as he is likely to hear "pull the cat's tail"), so rephrase it with what to do instead "let's pat the cat gently, oooh, see how the cat loves being stroked?" and guide his hand in a gentle action. It is best for any changing of these types of things to show the desired action and thereby ignoring the one you don't like, but not ignoring the child - if that makes sense?
HTH
