How to upload XML file into ABAP internal table?
Use IMPORT_FROM_FILE method of CL_XML_DOCUMENT to upload XML document.
Use the SAP function module KCD_CSV_FILE_TO_INTERN_CONVERT to upload a CSV file from presentation server.
First you need to upload the logo using tcode OAER to display it in ABAP ALV header .
To upload a file from SAP application server use OPEN DATASET, READ DATASET and CLOSE DATASET ABAP statements.
To upload a file from SAP presentation server using ABAP use function module ‘GUI_UPLOAD’ or ‘GUI_UPLOAD’ method of ‘CL_GUI_FRONTEND_SERVICES’ class.