If I remember well from the times we had Religious Education in primary school (I am a Greek Orthodox), the egg symbolizes Christ in the tomb. We hardboil and paint eggs red and on Easter Sunday we crush them in pairs saying "Christ has risen" and the other person replies "Indeed he has risen". The red color is for the blood of Christ and the crushing of the shell is symbolic for the defeat of Death, just like Christ managed to get out of the tomb by breaking the stone that was covering the entrance. Mind you that the egg is a symbol of life both because of its nutritional value and because it bears a life in it.
Now I'm guessing the chocolate is just our greedy nature, but there might be some tradition behind it as well.

Isn't cool to look for customs, traditions and their origins among different religions and cultures?

Oh! And Happy Easter!!