I don't want to be "that guy", but I'm gonna be... You shouldn't feed birds. For a bit of a once-off novelty I'm sure no harm done, but processed meats are really bad for them. There's also the issue of reliance on humans, increase in bird population, etc.

Leaving water out is a great idea though. Your balcony looks like a pretty sweet spot to throw a bird bath which will still attract plenty of birds without the potential feeding side effects. Shallow and wide is best cause they like to be able to see the bottom. Heaps of options on Amazon/eBay etc, or just make your own!

I stuck one on an old tree stump and went a bit stupid... Stuck an undergravel filter from a fish tank, lined the bottom with gravel to make it shallower, then used a solar air pump and a riser made out of PVC to create a nice little filtration system for it. Works awesome and there's always birds hanging around it. Water stays crystal clear instead of the algae it used to grow because water + sun + organic material = algae usually. Here's an old photo, the ferns have all grown up around it and there's moss everywhere around the base now. I should take an update shot.