Small size required (1-10 length, a-z, 0-9, Symbol 14 !@#$%^&*()-_+=) for a rainbow table needed for the hash would be around 438TB.
Even assuming you could store each possibility in a single byte, which you can't, that would still take about 86PB to store. Considering you would need to store both the key and the hash in order to have a useful table, it seems you would actually need to have a few exabytes dedicated to this.
There is a diminishing-returns limit to how small your rainbow table can be before it starts getting both false positives and false negatives, and bigger password domain makes it worse, but they require less than 1 bit per covered password.
(50^10 + smaller terms) * 256 bits (SHA256 size) Number of hashes * size of hash to store.
Obviously this isn't how it's actually done. The best page I found describing the process is: http://www.freerainbowtables.com/en/faq/
The forum is fascinating: http://www.freerainbowtables.com/phpBB3/uncracked-hashes-f23...