Before answering this question, it is necessary to understand what asyndeton means. Asyndeton is a very common literary techniques that involves the omission of expected conjunctions from series of words, phrases, or clauses.
A classic example is the following famous statement made by Julius Caesar after military victory:
I came. I saw. I conquered.
This is an example of asyndeton because Caesar omits the expected conjunction "and." If the conjunction had been used, the quote would have been like
I came, I saw, and I conquered.
Jonathan Swift does not use asyndeton frequently, preferring to use "and," "but," and "or" whenever those conjunctions would be expected to appear. However, there is a notable instance of asyndeton in one of the last paragraphs of "A Modest Proposal."
In this essay, Swift lays out a satirical, tongue-in-cheek argument for the use of infants as food to solve Ireland's issues around poverty. Having made a number of points along these lines, Swift lists a number of other "expedients," or solutions, to Ireland's economic problems, beginning each new item with "of." The final two items are set forth as follows:
Of teaching landlords to have at least one degree of mercy towards their tenants. Lastly, of putting a spirit of honesty, industry, and skill into our shop-keepers. . . .
There is a notable lack of any conjunction at the end of this series of ten ideas, which has the effect of emphasizing their number. This contributes to the broader ironic aim of the essay in that the ideas listed here are clearly more reasonable than the eponymous proposal of eating infants.