Hi Marina Debrova,
We can use single internal table and work area for two functions, but you should maintain clear function.
like.
Start-of-selection.
Clear : IT_DOCDATA
IT_PACKLIST
IT_ATTACHMENT
IT_BODY_MSG
IT_RECEIVERS
WA_DOCDATA
WA_PACKLIST
WA_ATTACHMENT
WA_BODY_MSG
WA_RECEIVERS.