There is a great deal of satire in "Gulliver's Travels." In fact, since the whole thing is intensely satirical, that makes it hard to pull out specific individual lines that are satire. (The satire is more in the content and the form as in specific lines.)
However, that said, here's a nice small example. In Chapter 2 of section on Lilliput, you'll find this line: " I had, as I before observed, one private Pocket which escaped their Search, wherein there was a pair of Spectacles (which I sometimes use for the weakness of mine Eyes)"
Since this is found directly after an official inventory of Gulliver's possessions by the government, it is a satirical comment on how much officials can miss. This is a giant with poor vision—and they can't even see his glasses!
the best satirical part is the end of the last chapter of the second voyage, where judges, soldiers, lawyers, politicians etc are severely criticised. if you talk of this portion it would be much better