1) King Ahasuerus levied a tax on the land and on the islands of the sea.

COMMENTARY:  I think that the storyteller includes this to say that King Ahasuerus stopped financing his administration on bribelike donations from the likes of Haman, but I have no idea, really, why this is here.

2) All the acts of his power and valor, as well as a detailed account of the greatness of Mordecai, whom the king promoted, are recorded in the chronicles of the kings of Media and Persia.

COMMENTARY:  Chronicles which we don’t have.  It’s tempting to say that neither did the story’s original audience, but Jewish culture put such a high premium upon scholarship (and still does) that I’m inclined to say that such documents might well have existed and that people in the Jewish community had access to them—because sooner or later somebody would not be able to resist the temptation to go looking for them.  To this day perusing old, untranslated Hebrew texts is a popular Jewish hobby, arguing minute points of grammar and context.  They would love footnotes like this precisely so they could look them up.

Which doesn’t automatically mean that the Chronicles of the Kings of Media and Persia didn’t also include works of fiction.  But at least they’d all be on the same page.

3) The Jew Mordecai was next in rank to King Ahasuerus, in high standing among the Jews, popular with many of his kindred, seeking the good of his people and speaking out on behalf of the welfare of all its descendants.