Depends of the source.
xls file or txt or qvd file you will use Load * from file.qvd;
From a databse (fe SAP erp) you will need to use a connector (ODBC or other). For Sap it gives:
Select * from Table;
Resident is when reading internal table.
first load external table:
Load * from data.txt;
//then read in a second time from internal table:
Load * resident MyTable;
hope its clear.