When I brought up Tolkien Reading Day on Friday, my buddy T.R. Knight (see his blog here) tweeted that he was "just starting to read 'The Fellowship: The Literary Lives of the Inklings'" and shared a goodreads.com review link here so I looked into the book a bit further. I had heard of the Inklings and knew Tolkien and Lewis were members but not much more than that. It certainly looks like an interesting book that tabletoppers of many stripes would find enjoyable.
Of the other two Inklings mentioned on the cover of The Fellowship, Owen Barfield might be the better known because his daughter Lucy figured so prominently in the writing if C.S. Lewis. Lewis named one of his main characters after her and dedicated The Lion Witch and the Wardrobe to her:
My Dear Lucy,
I wrote this story for you, but when I began it I had not realized that girls grow quicker than books. As a result you are already too old for fairy tales, and by the time it is printed and bound you will be older still. But some day you will be old enough to start reading fairy tales again. You can then take it down from some upper shelf, dust it, and tell me what you think of it. I shall probably be too deaf to hear, and too old to understand a word you say but I shall still be,
your affectionate Godfather,
C. S. Lewis.
Even more information can be had on Owen Barfield at barfieldsociety.org here.
However, more germane to tabletop gamers might be the work of Charles Williams. Like that of Tolkien and Lewis, he wrote some of his material in the fantasy genre. I haven't read anything by him but now that I am becoming more familiar, I plan to rectify that in the future. Some say Descent into Hell (1937) is his best work but after reading some summaries, I think I will start with his earlier Many Dimensions (1930) or maybe The Place of the Lion (1931). I'm going to dig around for some more information and reviews before I decide so if you know anything, let me know in a spoiler-free manner, please. Thanks!