Little confusing your description but

if what you want is when the user selcts the month form drop down and the product from drop down it populates sheet 2

Then you could use a combo of if statements and vlookups

for instance in your sheet two

if(B1=product1, sheet3!A1,if(b1=product2, sheet3!A2..... and so on

In sheet 3 you would store your v\hlookups and table arrays for this
you would have a table array for each product, and a v\hlookup for each product.

There prob is a way to do it with vba but that is beyond my knowledge at present.