Hyperbole

hyperbole: figure of speech using deliberate exaggeration or overstatement. Not intended literally, hyperbole may be humorous or serious
Your beauty, that did haunt me in my sleep
To undertake the death of all the world,
So I might live one hour in your sweet bosom
                                 --Shakespeare, Richard III

"she met the little urchin whose marvelous feats of gastronomy have been recorded in the earlier pages of our narrative,"
                                                                                    -The House of the Seven Gables
                                                                                            by Nathaniel Hawthorne

The "marvelous feats of gastronomy" Hawthorne references here simply consist of a little boy eating a few gingerbread cookies, nothing spectacular for any little boy when given the chance. However, by referring to them in this way and making them up to be rather grand, Hawthorne humors audience. The reader laughs, as Hawthorne injects some humor into a melancholy "goodbye scene;" Hawthorne uses the hyperbole as a form of comic relief.