Is there an area for a picnic lunch? Thanks.

U can pack a picnic and lay a blanket anywhere in the gardens

Yes there is.

There are two buildIngs in the center, one of which houses the restrooms. Between them, there are tables and chairs where you could eat. You can't just sit on the grass in the gardens and have a picnic.

There are benches and a gazebo, I can't recall if there were picnic tables though.