I've lived in Japan for so long now that paying at restaurants in other countries where it's done at the table seems so awkward.

In Japan, you don't pay at the table, you get up when leaving and pay at the exit. If you're at a high-end establishment entertaining guests, this also leaves you the opportunity to "go to the restroom" late in the dinner and pay ahead of time so that the "mess" of payments is completely forgotten.

It also means waiters don't need to run around the place with cards/readers/cash, you don't need to fumble when you left your wallet in your coat that's been hung up, don't need to squint to read receipts in the dim mood lighting in the eating area, etc etc.