Other than the manufacturer's site, there is literally nothing out there about these tables. There is one site, mercantila.com, that sells these tables, and there are a few reviews there, but none really about table quality or playability. (But those who reviewed and said that they bought a pool table seemed to be happy with the purchase.)
Anyway, they seem brand new, and they are probably made by an overseas manufacturer/mass-producer, and then the KGI name is just put on them. Similar grade tables, I'd think, would be the Spencer Marston Pool Table, American Heritage Pool table, and the American Heirloom Pool Table that are both discussed in the same context. These, I believe, are all made overseas with lower-quality material, probably by the same one or two manufacturers, then re-branded for North American resellers. You always see these at discount online billiard table sellers, or big-box retail stores like Costco.
If you are a beginner, these tables should suffice, but if you are a more advanced player, or if you play in tournaments, you may want to consider going with a billiard table that has a trusted name and proven quality.