Salarino and Salanio are given the task of presenting information to the audience in Act II, Scene 8, because they can give candid reports about other characters and because they serve the important function of establishing foreshadowing. It is not until after the Romantic period that unreliable characters are introduced in literature, so it is a forgone conclusion that, while friendships and roles may bias the delivery of information, the information is trustworthy.
Renaissance drama is built upon Greek drama in which the Chorus is routinely used to tell the audience important information about characters, character motives, actions, and events that aren't acted out by the principles on stage. Shakespeare kept the function of using non-principle characters to convey needed additional information but he substituted the Chorus with three other kinds of characters. The first is the Fool, an urban character who is a favorite at court and jests with and about the primary characters letting us know more about the deeper thoughts, traits, and motives of the principles.
The second is the Clown who is similar to the Fool except that the Clown is country bred and uneducated and leads the audience to a deeper understanding of the primary characters by blundering along without knowing what he is really doing. The third kind is that of which Salanio and Salarino are representative: minor characters who fill the place left by the elimination of the Chorus and who reveal important information to the audience about the primary characters and events because they have privileged positions and know things that others don't.
In this capacity, Salanio and Salarino tell about Shylock's reaction to the devastation of his daughter's betrayal, elopement, and early access to her inheritance (some of which is Shylock's present working capital) and they tell about Lorenzo's and Jessica's flight from Venice and they tell about Antonio's private conversation with, feelings for, and instructions to Bassanio. They also tell that a ship has been lost in the English channel and that they suspect it might Antonio's, which foreshadows his loss and his upcoming trouble with Shylock: "Let good Antonio look he keep his day [on which to repay his loan], / Or he shall pay for this [through Shylock's demands]."
The two observers of Shylock, Solanio and Salario,are altogether biased. They have unlimited sympathy for Antonio but no sympathy for a Jewish father, robbed and deserted by his daughter. Theymake fun of Shylock and can't see that he was undergoing an extreme shock and derangement. Shakespeare does this to bait his audience's prejudices, probably to avoid a backlash to himself for sympathizing with Shylock. Notice that after Portia makes a world famous speech on mercy, she and the court give no mercy to the Jew. He is plundered of ALL his wealth and forced on pain of death to convert. Close attention to details of the play reveals the poet's sympathies with the Jew and not his callous enemies. Shakespeare gives much evidence that Shylock does not intend to collect his bond of flesh, only to get Antonio to beg for mercy -- evidence continually overlooked because of the bias of audiences.
Read further details in the following web site: