The Milton of the original village comes from Middleton, suggesting that part's not after a person but after the geography. Keynes is debatable whether it's a single person or the entire de Cahaines family. Who also, incidentally, gave their name to Horsted Keynes in Sussex, and therefore by extension to the station now on the Bluebell.Milton Keynes is named after *two* people! (well, sort of).
Ham is (I think) a Saxon word for farm, so a lot of -ham settlements will be named after the farmer. In a similar theme, Uckfield is named for it's origin as Ucca's field, and I suspect that there are others.In my primary school days, I read that Beckenham was Becca's Ham (farm?), so there's another 3 for you. I suspect there are many similar.