This is a short little text Carroll wrote to introduce children to logical reasoning, specifically set logic of the "Some Cretans are Liars" variety. At the time, it was probably an excellent work for this purpose. There are two reasons why it's not that great a text for that today, though, at least not in this kindle edition.
The first is that Carroll's tone here has aged pretty badly. To begin with, his overall tone is at times painfully precious, in a way that would probably put off any modern child reading this text; beyond that, the examples he chooses are. . curious by modern standards -- for example, the second set of extended examples centers around the two propositions ""All Dragons are uncanny" and "all Scotchmen are canny."
The bigger problem is that the whole mechanism of the book revolves around a square grid diagram that simply doesn't translate in this kindle edition -- it just appears as a set of ||||'s next to each other. Which makes the book's arguments comparatively difficult to follow, for all Carroll's wit and charm.
Those two issues aside, Carroll's text does a good job of explaining basic logical theory in a way that children can understand. But, unfortunately, this edition is more a historical curiosity than it is anything else.