You can use the following file as a solution.
There you have to define the name of the sheets to load in the script.
If you want to load Except 'Master File' Sheet, you can use the following coding.
for each vSheetNames in 'Product1$', 'Product2$', 'Product3$', 'Product4$'
Hope this helps
if you are using QV on a win32bit environment (where you can use OLE Jet), you can use the example posted by Celabarasan: http://community.qlik.com/message/195769#195769
You just need to adapt the script to read tables that start with 'Product*'
Hope this helps,