Welcome to the Bunnings Workshop community. It's awesome to have you join us, and thank you for sharing your question about wanting a plan for a classic picnic table.
Just to be a bit more specific. Are you referring to the classic "A" framed picnic table that seats six people? Or were you referring to the hand-carried leg fold-away type? Would it be possible for you to post a photo or picture of the picnic table that you're referring to? Once we see what you have in mind, our members will then be able to make recommendations on how to build your picnic table.
Here are some fantastic picnic tables that our Workshop members have shared.