The workshop will take place at Queen Mary University of London, in the Computer Science building, room BR3.02. The department is on Godward square, which is at the black dot on the map below. The easiest way to access to the workshop room is through the Bancroft road entrance (red dot on map -- the room is on the 3rd floor).
Queen Mary is located in central-east London, with nearest tube stations being Stepney Green (Hammersmith & City, District) and Mile End (Central, Hammersmith & City, District).
We know of the following hotels that are reachable on foot in ~20 mins: Ibis Budget London Whitechapel (£), Travelodge Bethnal Green (£), Whitechapel Hotel (££), Holiday Inn Commercial Road (££), Town Hall Hotel (£££). Most of these are in the Whitechapel area, and the previous list is not extensive.
Moreover, several accommodation options in central London and London Stratford are easily accessible by tube.