débit here is in the sense débiter = cut into pieces, nothing to do with débit = rate, throughput rate, etc.

So:

Material cutting: - place sheet on plasma (cutting, presumably) table
- place sheet so as to be perfectly parallel to the ....

...guide or feed mechanism, or something like that. Don't know if the chemin de roulement is the mechanism that displaces the plasma torch, or if the torch is static and the sheet moves.