This is the 17659th most frequent Polish word.
zjada
"Zjada" means "eats" in English.
In this sentence, 'zjada' refers to the dog's action of eating food completely.
Mam psa, który zawsze zjada jedzenie, które mu daję.
I have a dog who always eats up the food I give him.
Here, 'zjada' metaphorically describes the machine swallowing or consuming paper.
Zauważyłem, że nowa maszyna zjada papier podczas drukowania.
I noticed that the new machine consumes paper during printing.
In this case, 'zjadałaś' expresses the action of someone having eaten the cake, indicating completion.