Definitely enough tables as far as space goes. If it's a weekday party, I would recommend getting there before everyone else has had time to get things together after work. Weekend parties tend to be busy unless you get there before 11 am.
My experience is that there would be availability. Don't think they can be reserved.
Yes there are
Yes there are picnic tables in the back that I and others have used for birthday parties and other events as well.
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