ID on a potential flint fossil
Assuming that the identification of the rock as Flint/Chert and not Limestone/Dolomite is correct I'd say it's a formation artifact rather than a fossil. What I mean is that at some point as it was forming, flint can form in two ways one is due to silica saturated water acting on limestone and the other is by direct precipitation from mineral saturated water in shallow environments, the small bead-like structures were created within or on the surface of the rock. It may be a surface impression from a fossil that was once part of a larger piece but as it is now there's no evidence of a material difference between "fossil" and the country rock of the flint. This opinion is coloured by the fact that here in New Zealand fossils in our flint are vanishingly rare, I'm not sure if that holds in England though.