Indeed, however the routeing guide says:
"As the shortest route for any journey is always a permitted route, this can be checked, and the distance between stations calculated, from the National Rail Timetable. Mileages appear in the station column at the beginning of each major table, except table 51. To arrive at the throughout distance for travel between every station by any route, add mileages together for the component parts of the journey by referring to the relevant timetables. "
The timetable says
"Look up your destination. If it appears in up to five tables, those tables are listed (for example Hilsea appears in Tables 156, 157, 158, 165 and 188). If it appears in six or more then there may be sub-divisions. If your destination is subdivided in this way and your origin is NOT shown (for example Shipley is not shown under Lancaster) then look up the origin instead as it probably has fewer tables. Alongside the station name is shown a two character code indicating which operator is responsible for operating the facilities at that station (see also Train Operator pages)."
"If your journey is more complicated and involves several changes between tables, the Timetable Network Map will be very useful."
The London and Southeast map is admirably clear, and clearly shows the tables required:
http://www.nationalrail.co.uk/passenger_services/maps/NetworkRail_L&SEmap.pdf