Right on my doorstep! Home ground of Bridon Ropes and Meridian VP, between Charlton Park and Woolwich Common.
The couple of times I've been to see Bridon they didn't allow drinking pitchside, but there is a bar there.
Since the sad closure of the White Swan, nearest good pubs are the British Oak on Old Dover Road (ace beer garden if it's sunny) and the Green Goddess craft place at Blackheath Standard, both about 15-20 minutes' walk away.
(Engineering works mean there are no trains to Charlton that day, but you can get the 89 or 178 bus from Lewisham to Charlton Park Lane (if you've been to Charlton Lido you'll know the stop) then walk down Charlton Park Lane to the ground. Or you can get a 53 from New Cross/ 486 from North Greenwich to Charlton Park Road and walk through Charlton Park.)