You either save the excel sheet as Tab delimited file or .csv file.  and declare your internal table to get the corresponding the contents from the file.   Then when its tab delimited or .csv, SPLIT the contents into respective fields. 
Here is a sample for CSV file : 
*declaration of internal tables. 
DATA : BEGIN OF IT_DUMMY OCCURS 0, 
         TEXT(500), 
       END OF IT_DUMMY. 
DATA : BEGIN OF IT_MAIN OCCURS 0, 
         MATNR LIKE RMMG1-MATNR,           "material selection to change 
         DISLS LIKE MARC-DISLS,            "lot size key 
       END OF IT_MAIN. 
*uploading the input file*********************************************** 
CALL FUNCTION 'UPLOAD' 
    EXPORTING 
         FILENAME            = INPUT 
     TABLES 
          DATA_TAB            = IT_DUMMY 
     EXCEPTIONS 
          CONVERSION_ERROR    = 1 
          INVALID_TABLE_WIDTH = 2 
          INVALID_TYPE        = 3 
          NO_BATCH            = 4 
          UNKNOWN_ERROR       = 5 
          OTHERS              = 6. 
*appending it_main by splitting the uploaded file 
LOOP AT IT_DUMMY. 
        SPLIT IT_DUMMY AT ',' INTO IT_MAIN-MATNR IT_MAIN-DISLS. 
        APPEND IT_MAIN. 
ENDLOOP. 

 Serkan AKKAVAK
Computer Engineer
ABAP Developer & SAP MM SD Consultant
Contact : serkurumsal@yandex.com