Most veg are fine; just avoid onions and raw potatoes. I have heard tomatoes aren't reccomended. For fruit avoid grapes and avocado, and the pips of apples, pears etc.
Why avoid the pips of apples???
If you are worried about the nasty poison they contain, then don't be. Its not worth worrying about. For a dog, or human to be poisoned by apple pips then the consumption of apples would have to be a ridiculous amount in one sitting, it would not be possible, not in a lifetime.
Back to peas, frozen peas were jackpot treat for may old dog Poppy. Of course, only really used at home and short walks, and in autumn winter time. Every time the freezer was open she was there, hoping and praying she would get a pea...well she did sit nicely!