On the rare occasions I get to eat out I find the waiter asks after about 1 minute if you're ready to order, if you're not ready then it can be 20 mins before they'll even pass your table again ... presumably the computerised seating plan/order system records average times [from seating to ordering] and the waiters are prompted appropriately (slightly early if the restaurant wants to push orders through faster)?

It's strange. I've had waiters ask if we're ready before everyone at the table has even closed their menus. I recall being taught to use the menu as a signal for whether you're ready or not. Is that not a thing anymore?

I don't necessarily think it's a thing that waiters know about these days - in my (admittedly limited - I'm more of a sandwich and fast food guy) experience of eating out, closing the menus doesn't seem to trigger interaction any sooner.