Oh, I missed this one.
38 hour average working week, how many rest days per week and rest day pattern depends on depot. Sundays inside the working week, paid at normal rate, but currently no Saturdays at all are rostered and very few Sundays are.
You'd (as the name suggests) mostly be looking after the First Class carriage, greeting passengers, serving food and drink, keeping the carriage tidy, assisting passengers with enquiries, helping with bags etc.
You'd also assist the Retail Service Manager, preparing hot sandwiches for standard class passengers, doing litter picks through the train and just generally being "useful".
In the event of disruption you'll be communicating information to passengers, assisting the RSM and Train Manager where needed, and catering crews are trained to assist the Train Manager in evacuating a train if necessary although that one doesn't tend to come up that often!
Overtime and Rest Day Work is paid at normal rate and off RDW or a Spare Turn (which is where you don't have a set job until at most three days before) you can pick up either a FCH job or an RSM job (doing the retail service in standard). If you pick up an RSM job then you get paid extra for doing higher grade duties.
Catering staff don't "sign" specific routes or traction so you can pretty much be sent anywhere and work Voyagers or HSTs - 170s have no onboard catering facilities so in the unlikely event one of those turned up you'd just "assist" - ie, just be about.
Well regarded as being one of the best jobs in the company, pay isn't the highest but it's a straightforward, mostly relaxed job, you're not assessed on sales or anything like that and working in First Class the standard of passenger is usually a bit higher so there's less grief and generally fewer physical assaults.
Good luck!