Yes
There is one large gazebo (I belive #1 or #2) that is popular for large groups and does have picnic tables under it. But you may have to bring more table and chairs to fit 150 people comfortably. You can rent any of them by the hour at any of the parks in the city. (Wildwood, 7th St, etc) You can call or go into the community center to get more information on pricing and if they have been rented out already.
They have a building you can rent
There are multiple gazebos with picnic tables under them. I'm not sure if the capacity but some of them are adjacent to each other. You should probably call the parks department and see if you need a permit. Los of places require them
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