Waiting and waitressing jobs in the UK are very different from similar jobs in the United States; in fact the same can be said for all restaurant jobs.
One of the big differences is in the custom of tipping. In much of the world it is customary for the customer to leave a tip for the serving staff and this tends to be between ten percent and twenty five percent of the cost of the meal including drinks. The tip is usually discretionary and it is supposed to reflect the level of service received, however some restaurants impose a service charge, typically of 10% in the UK but in the US it is usually around 18%. Where a service charge is applied to the bill in the UK it is not compulsory to pay it; by law the customer is entitled to refuse to pay it.
Throughout Europe restaurant staff must be paid at least the legal minimum wage, though this is not the case in all States in the US, and where there is no minimum wage the basic wage of waiters can be very low indeed. In some States, for instance in Virginia, it is not unusual for no wages at all to be paid. This means that whilst in Europe tips are welcome bonuses over and above the basic wage, in the US they can be the only, or more or less the only, source of income.
The result of this is that restaurant staff in the US tends to be considerably more friendly and obliging and provide a much better quality and standard of service and it is not at all unusual for them to receive a 24% tip or even higher. Throughout much of Europe apart from the UK tips are very much lower and quite often derisory; generally customers just round up the bill to the nearest Euro. In the UK tips tend to be a compromise between the two; ten percent tips being typical.
It is interesting that the actual size of the tip (rather than the percentage) is not necessarily related to the perceived quality of service. In one study carried out in the US it was found that there was very little correlation between the amount tipped and how highly the customer assessed the quality of the service. The biggest correlations were with the cost of the meal and how attractive the customer considered the waitress or waiter to be; which could account for the impression that waiting staff in the US tends to be in the higher quartiles of the attractiveness scale.
In Japan it is almost impossible to leave a tip as tipping is not part of the Japanese culture. In fact some Japanese waiters might feel insulted if their customers try to tip them. In Scandinavian countries a service charge is imposed by law and must be paid; it is unusual to leave an additional tip; and in much of Europe, as has been mentioned, only very small tips are left. However in just about every other culture tipping is generally welcomed even if it is not expected.