It is a melancholy object to those who walk through this great town, or travel in the country, when they see the streets, the roads, and cabin doors crowded with beggars. (1)
When Swift speaks of a great town, he refers to Dublin. He wasn't always so favorable in descriptions of his home country, but it sounds like he's being serious.
For we can neither employ them in handicraft or agriculture; we neither build houses (I mean in the country) nor cultivate land. (7)
Lazy absentee landlords typically built huge estates, further contributing to Ireland's poverty.
These […] helpless infants, who, as they grow up, either turn thieves for want of work, or leave their dear native country to fight for the Pretender in Spain, or sell themselves to Barbados. (1)
Here's a real life game of thrones: Catholic Ireland was loyal to King James Francis Edward Stuart (the Pretender) even after he was dethroned for his Catholicism.
The Proposer (Narrator)
For first, as I have already observed, it would greatly lessen the number of papists, with whom we are yearly overrun, being the principal breeders of the nation as well as our most dangerous enemies. (20)
Swift is satirizing English gossip that Irish Catholics would rise up and restore the Pretender to the throne.
I desire those politicians who dislike my overture […] that they will first ask the parents of these mortals whether they would not at this day think it a great happiness to have been sold for food at a year old in the manner I prescribe, and therefore have avoided such a perpetual scene of misfortunes as they have since gone through by […] the want of common sustenance, with neither house nor clothes to cover them from the inclemencies of the weather. (34)
Swift shows the gap between what he views as two separate Irelands: the hoity-toity politicians and the very real economic burdens of poor Irish citizens.
But I am not in the least pain upon that matter because it is very well known that they are every day dying and rotting by cold and famine, and filth and vermin, as fast as can be reasonably expected. (18)
The conditions may be slightly exaggerated, but Swift is trying to tug at the heartstrings of wealthy Irish readers.
I desire the reader will observe I calculate my remedy for this one individual kingdom of Ireland, and for no one that ever was, is, or, I think, ever can be upon earth. (28)
Just so we're clear, Swift isn't proposing that the whole world turn to cannibalism. Just Ireland will do for now.
For we are told by a grave author, an eminent French physician, that, fish being a prolific diet, there are more children born in Roman Catholic countries about nine months after Lent than at any other season. (13)
Here's another satirical reference to Ireland's Catholicism and the Lenten practice of eating fish. Fish was supposed to boost fertility.
As to our city of Dublin, shambles may be appointed for this purpose in the most convenient parts of it. (16)
Shambles are slaughterhouses. Swift is painting a picture of a lovely Ireland, isn't he?
Therefore let no man talk to me of other expedients […] of learning to love our country, wherein we differ even from Laplanders and the inhabitants of Topinamboo, of quitting our animosities and factions. (28)
Can't everyone get along? Get this: this was one of the actual solutions Swift proposed in an earlier tract.