Our family of 3 adults will be traveling by train on a Saturday morning at 9:00 from Southampton to London at the end of a cruise to Norway in mid May We have reservations at an air b&b in S Kensington but may not have access until 16:00 We would like to check our luggage and use the time to walk & have lunch before taking the tube to Gloucester Road. Aside from our ipads & personal items that we will keep in our day packs is this a good idea?
It depends where exactly where you are staying as the previous tube station before Gloucester Road is South Kensington (arriving from the Waterloo direction).
There is a left luggage office at Waterloo called Excess Baggage £10 for up to 3 hours or £15 for longer. There will also be app based left luggage (like Stasher as an example close by) for a lot less-around £5 a day.
Sure, I would do that rather than carry all that stuff around all day. And yes, definitely keep your high-end items with you. Here's the website for the Left Luggage at Waterloo Station—https://www.left-baggage.co.uk/en
You can pre-book or just go there directly with your luggage when you arrive. It's a bit pricey but for the time you're there, it shouldn't be too much. It's called the Excess Baggage Company at Exit 6 (Southbank) at Waterloo. For more info on location, visit here: https://www.left-baggage.co.uk/en/locations
note that at the Excess Baggage the charge is per piece and everything is x-rayed and under supervision. don't know how it works at the other