scene one: what is the effect of the actors eating without food or utensils at the beginning of the play?

I think Williams is trying to disrupt a sense of realism in the play. From the beginning, the figure of the narrator shows that Williams' play will not follow the conventions of realistic theatre. The narrator breaks the conceptual "fourth wall" of naturalistic drama by addressing the audience directly. In this way he is appealing directly to the audience rather than through his play. He wants to blur the lines between the real and the surreal before focusing in on his characters.