chopping block
Literal meaning: a sturdy surface for chopping or pounding food, such as meat or fish. Less common in modern daily life; the figurative sense is far more frequent.
See also: 叩く (たたく)
The cook pounded the meat on the chopping block.
draft proposal; tentative plan; springboard for discussion
Figurative business term: a rough draft or initial plan put forward to be criticized, refined, or built upon. Often used in meetings and project planning.
会議で使うたたき台を作ってください。
Please prepare a draft proposal for the meeting.
この企画書はまだたたき台なので、遠慮なく意見をください。
This project plan is still a rough draft, so please give your honest feedback.