The answer is: to make his use of verbal irony more effective
In Jonathan swift's essay, a modest proposal, he wanted to ironically complain for the current situation in Ireland by proposing a way to stop starving children by using them to the rich land owners, in order to make more effective the verbal irony he includes facts and statistics to support his proposal.
The word <em>whom </em>in this sentence is used as 2. object of a preposition. Since it can be found after a preposition <em>for, </em>it is object of a preposition.
