Is excessive salivation normal a week after wisdom tooth removal?

Yes: After the removal of your tooth your salivary glands become more active as part of the bodies healing process. There will be a combination of saliva and bleeding after the extraction. You should be rinsing your mouth out with salt water to keep food out of the extraction sites. Things will return to normal over time depending on how difficult the extraction was.

Is not uncommon: an temporary increase in the amount of saliva after wisdom teeth surgery.