Lilliput is a number of streets in miniature, located in the Lady's Ward. The Lilliputians are very small creatures: sprites, grigs, jermalaines, and miniaturized humans, tieflings and fiends. Everything they could need is within these doll-sized roads and buildings: food, shops, places of employment, touts, and tiny little portals to tiny little planes and realms.
There are even extraordinarily small dabus, who may be recognized as the same ones who minister to the rest of Sigil in a much larger scale. Exactly how the dabus change size is as mysterious as most of what we know about them. Unfortunately for the Lilliputians, the local razorvine is normal sized, but full-sized dabus come by regularly to trim it.