Home (or Gianthome) is the - surprise, surprise - homeland of the Giants, whence these oversized musclebound humanoids fare forth with castle-sized ships. Apart from fanfiction, the reader never visits this remote location of the Earth. Munificent depictions allow us to discover that it contains a harbor (d’oh), oodles of readily available granite, and some vague sea-standing rock called Salttooth around which apprentice sailors like to race.
If the author’s fawning over Norse mythology and Wagner have not so far become apparent from all the allusions to World Trees, rune-carved magic staves, svartálfar, and so forth, this slams a Viking helmet on top of the cherry cake. Jötunheimr, the land of the Frost/Rime Giants, translates directly as Gianthome. If anything can be deduced from this, including the florid language of the BFGs, their inherent ability to withstand cold temperatures, and the native minerals, Home just might resembe an alternate universe Finland down to the inanely cumbrous grammar, kilometer-long words of Fenno-Ugric tongues and the national rock, granite. You may therefore bank on there also being birch trees, conifers, mountains and so much snow that one might choke on it.
The actual number of Giants remains ambiguous as well. Once in the dawn of tides, two thousand of their kin set sails to discover new wonders beyond the seas, and this amounted to a sore loss among the unfertile race. Hence, mere tens of thousands of them might populate the far-flung homeland. At least in the event of any frankly foolhardy human enemy invasion, they'd require but a handful of berserky Amazon warriors with ten-foot swords to defend the realm with total success.