Wagamama is a chain of Japanese-style noodle bars. For the first few years they only had three restaurants, all in London, but recently they've been opening more and more. Now there are something like 9 or 10 restaurants in London and maybe 5 or 6 in other cities.
The thing about Wagamama that was totally radical when it was introduced is that it has several long bench tables that can seat about 12 people each side. Often you sit beside total strangers, and it's one of the few places I know that I feel comfortable going to on my own with a book. Inside the menu it used to say "Wagamama was conceived as a non-destinational food station"(!). It was designed as a place that people pass through to eat a quick, but reasonably wholesome meal on the way to somewhere else.
Obviously, this hasn't worked. You simply can't have a non-destinational restaurant that serves good food - anywhere which does good enough food will become a place that people go to on purpose. They must have finally realised this - the amount of times I've seen parties of 10 or more turn up and have to wait around while a large enough space is cleared for them. Doing group bookings is definitely a good idea.
The newest Wagamama, "Wagamama Haymarket" (actually located on Norris Street, just off Haymarket) is interesting in that it doesn't just have the large group tables - it also has some small tables located in alcoves. But they don't seat 2 - they're for 3!