You only really see these guys in the very beginning when they come to tell Barabas that Ferneze's rounding up all the Jews at the Senate House. Unlike Barabas, when Ferneze offers them the opportunity to give up half their estate instead of converting or giving up everything, the other Jews fold immediately and give up half. They try to console Barabas after he loses everything by reminding him of the Biblical story of Job, but he basically covers his ears and goes "nyah, nyah, nyah."
Here's the most interesting (to us) thing about the other Jews:Barabas, who is relentlessly characterized as Jewish and defined by his Jewishness, isn't buddy-buddy with them. You can't see him being the secretary-treasurerof the Jews of Malta Society, if you know what we mean.
And what we mean is that Barabas actually thinks they're idiots ("base slaves,"if you want to get specific), because they accept their fate at Ferneze's hands and try to make the best of it, instead of fighting back, like Barabas does (with gusto! And poison!). Early on, Barabas acknowledges the Jews as "a scattered nation" (1.1.118), and not one that he necessarily identifies with.