It's my manor, do you want a roll-call? Chains a-go-go, mainly on the pricey side. Giraffe is ok, but always rammed at weekend. There's a Strada, a yo sushi and a Wagamama and Eat for sandwiches etc. Up on the top level a tapas place, le pain quotidien, a sushi place, a brilliant Chinese place called Ping Pong. Round the back, a Pizza Express, another Italian of more reasonable price bracket called Azurro on way to Waterloo Station.
All the theatre/music venues have their own self-service style cafes. There's a road behind Southwark Tube with a bunch of cheaper places: a great Thai (Thai Silk) a greekish/mediterranean, a burger place and another bunch of more independent walk-in places on The Cut and Lower Marsh, which are much better value. But obviously, if you want to stay closer to River, you pay a bit more.
Wow....................my own personal adviser! Thank you! Just been talking to sil and now she is changing her mind. She thinks we should tube it from HMS Belfast back to Kensington, too long a walk for the twins. So now looking for somewhere nr the Natural History Museum.............
Well... There's another Strada by HMS Belfast, and various other bits and pieces in More London complex. I could go on....my intimate knowledge of the South Bank is verging on the nerdy . There's a great sandwich/salad place behind City Hall called Amanos, not sure if licenced, but does take-out and Potters Field Park is quite nice if sunny.
Don't go to cafe in Nat Hist Museum, bit of a hole, especially in school hols. V&A much nicer, but still busy.
Sadly, because I live here, my knowledge of hotels is lacking. Of the cheapy-chains, Mercure, Holiday Inn Express and Premier Inn are usually ok (based on other cities for basic overnighters) but i don't know if there are any in Kensington, i'm afraid.