Hey there!
I'm not entirely sure if you mean having a single form without that form being part of any specific table. Meaning you could use all your base's fields. If you meant that, then that wouldn't be possible.
However, if you're referring to having a form in x1 Table and whenever that form is submitted (filled), that information being sent to x2 and x3 Tables. That would be possible with Automations. (Using Trigger: When form is submitted and the Create Record block)
Let me know if I made some wrongful assumptions and I'd be happy to help
