I understood it this way:

OpenTable sounds like it would be open-source, but it appears that it isn't

I think the parent comment to yours made a sarcastic take using a variation of the popular ambiguity Free as in Beer [1] that usually differentiates between free as 0 cost and free as freedom as a reaction to the OpenTable software being free to use rather than open-source

[1] https://en.wikipedia.org/wiki/Gratis_versus_libre