The conference will be held in the Department of Computing of Imperial College London. The department has instructions how to get to college. Please note that car-parking near college is limited and very expensive.
Two places the organizers can recommend are for instance, the Queens Arms which provides traditional British pub food, and there is Jakob's which is a restaurant. There are also plenty of other restaurants along Kensington High Street, Gloucester Road and near South Kensington tube station.
Here is a short list of things to do outside the conference. This is by no means all you can do but just a very small and biased selection starting off with places to eat.
There are three famous museums in (less than) walking distance.
A bit further away are parks and palaces:
Everything listed below can be easily reached using public transport. London also has an affordable Bike Hire Scheme which might be a convenient alternative to the Tube on a sunny day.