Hi,
Several Approach can be followed to achieve your requirement .
on click of mail triggering button take all internal table data to make a pdf and attach that pdf to mail as normally we do to send smartform as attachment to mail.
or take data of internal table to excel format and then attach that excel to mail and send.
Fm need for mail send is SO_NEW_DOCUMENT_ATT_SEND_API1 or You use Oops class for mail sending