Which continent? At least here in the States (near Lake Tahoe specifically), there are plenty of 8+ table restaurants that don't have their own off-street parking. This has been the case in pretty much every American downtown I've visited; most drivers rely on either roadside parking spaces (usually metered) or dedicated parking garages/lots instead.
The main exception I've noticed is Reno (along with the Nevada side of Tahoe), given that the bigger casinos - even in "downtown" areas - will typically provide parking garages for their guests.
Some pre-code buildings are grandfathered. Minimum parking was mostly phased in between the 1930s and 1960s. You can't build a new restaurant without parking except in a very, very small fraction of American urban areas.
I'd imagine that restaurants in urban centers are rarely "built" nowadays; in downtowns, you're probably leasing (or maybe buying) an existing building.
The main exception I've noticed is Reno (along with the Nevada side of Tahoe), given that the bigger casinos - even in "downtown" areas - will typically provide parking garages for their guests.