Nanex Nxcore provides the full OPRA feed including CBOE best bid/offer real time for all US options for a few thousand per month, or just the OPRA top-of-book for somewhat less, and that is real-time; their historical data are in the same format and are somewhat cheaper than real-time. It comes in a format that is accessed via an API, although I think you can extract it quite easily to a spreadsheet using their tools (not that I would recommend that as the data are formidable for options these days).