Waiting staff in UK are usually earning minimum wage I think, which is £5.73 per hour if you are over 22 (7.36 Euro).
As for tips, its not so common in cafés outside of London (I worked in a café in Bath for 5 years, never got tips and i wasn't *that* bad!!), but in resturants where food is served you give between 10-20% of the meal price. Most commonly would be about 15% I would say :)
When my mother used to waitress, she would get between £50-£100 per night usually (64-128euro) - as the tips the whole resturant got were shared equally between all of the staff.
Hope this helps!