1) Apple
2) Salami
3) Chicken

If the pieces are small enough to go into their mouth, would it be okay for 'em?

apple is perfectly fine as a occasional way to vary their diet, however not very many goldfish actually like it much.

Chicken and salami, no, goldfish cannot digest mammilan animal fats, and over time it can cause fatal "fatty liver".

I wouldn't give any luncheon meats or anything that high in nitrates, salts and preservatives.