Hello, there are a few steps 
You'll have an oracle table, and an excel file (you can more too).
with the help of a mouse, right-click and you'll find an option to import data 
you can select the import file and verify the data in the file too 
after this, you can create your script and import it automatically after this please select the columns that need to be imported 
now you have to map the excel columns to table columns
verify your setting and click on go and then click on finish 
this shud be done, with these steps u can export the files