Do you take reservations for a picnic with about 25 people? If so, how much?

Depends on your space

It's $300 to rent a space

It's first come, first served for picnic tables and barbecues. There are large group gatherings all the time :)

No you can not rent the areas. Not supposed to have parties but if a group of people meet up for a picnic no one is going to mind.