why do restaurants have tables so close to the bathroom?

Believe it or not, some people will eat at those tables. That's why restaurants put them there. They are trying to make the most of the use of the space there.

Some people like to eat and run

To piss off single male diners.

To maximise the seating / customers.

It’s unprofitable to have a section of the restaurant dining area which cannot generate revenue. 

So there are tables placed close to lavatory entrances. 

Some people actually prefer them, especially those who need fast and frequent access. Others prefer them for personal security reasons, whether real or imagined: from that position they can see most other customers and have a quick bolthole to dash into if they need to hide.

Customers who do not wish to be seated near to the lavatories can ask when booking not to sit there or can refuse the table if offered it as a casual walk-in diner, but with no guarantee of other tables it’s often a case of “take it or leave it”.

to give u YA question inspiration

It's the way they are set up