M.,
Children understand 'no' very early, indeed. They learn quickly and well, provided the lesson (they may need to repeat) results in the same outcome every time.
In this case, all she needs is a 1-2-3 lesson. I call it 1-2-3 because it's likely one of those situations that she'll repeat until she gets the same result 2-3 times in a row - and then you should see it come to an abrupt end (and, if not, she's got a superior dose of 'stubborn' - which will either add to or take away from her longevity...can't make any predictions for you on that! :-).
First time she does this, pick the food up, get down on her level, look her in the eye as you place it back on her table and say to her, "the next time you throw this on the floor, I will throw it in the garbage and you will not get any more until lunchtime - do you understand?" Allow her to respond to you - repeat the question if need be.
Chances are, she'll throw it on the floor again. Pick it up without any expression at all - just be calm easy in your being, like you're doing a product demonstration on QVC - 'hi folks, this is the function of the most simple appliance in our home - the trash can - waste goes in, lid gets shut so easily you'll say....*ahh, now THAT's easy*.
Put it in the trash (all a viewable activity from her location). Let her scream or throw whatever fit she wants - just say nothing.
When you can tell she's de-escalating, return to her and speak again at her level. Quietly remind her that you did exactly what you said you would do - and if she doesn't like that, she can choose to keep her food on her table and eat it, instead.
Again, that may not be too pleasing - if she's spirited as you say, you'll likely see the rest hit the deck and the rest of her emotions play out.
As long as you do nothing to respond other than allow her to have her feelings, she'll eventually calm down and you can then go back over and quietly tell her how sorry you are that she chose to throw her food in the garbage. Now there is none, and that is so sad for her.
Then, take the opportunity to move onto other activities (next product up on the QVC demo and will you be joining us today?) in a loving way - let her join you in whatever it is that's 'next' and move on from the experience.
As long as you keep your cool and remind her of HER power via HER choices, she'll figure it out and resolve it for you. Stubborn, spirited or whatever else it may be, what she really wants to know is what the outcome of her experiment will be each time she does it - if it keeps coming up different, like any good scientist, she'll have to keep experimenting until she can predict something with some degree of satisfaction :-).
Best to you and your little girl - have FUN :-),
T. B.