I would most likely calmly tell them that I am a citizen of the United States too, and I demand a table. If they still will not seat me, I would probably calmly exit the restaurant and find somewhere that will. That's on them for not seating someone because of their race or culture. Hope this helps~! ~Mistermistyeyed.
Telemachus responds to Antinous's reply in the assembly negatively and thought that he did not stand a chance to go against someone who is stronger and larger than himself.