Product and Index functions

I need it to do the following:
1. Find the last date given in a month base on row 5 in sheet2
2. Using the cell above's column find the average not ignoring zeros of rows 6-35

The end result for jan should be 7%(H would be the column), for feb it should be 23.5(F would be the column).

Since it is still about uncertain your actual requirement, I will go out on a limb and guess...

Here attached, I have extracted all products that fall under the latest dates in the table for the specific months indicated.

Firstly, I added a couple of helper rows above to get the last respective monthly dates, and the count of percentages over 0%

Respective formulas in C2 and C3 are:

=MAX(IF(TEXT(Sheet2!$F$5:$I$5,"mmmm")=C4,Sheet2!$F$5:$I$5))

confirmed with CTRL+SHIFT+ENTER not just ENTER

and

=COUNTIF(INDEX(Sheet2!$F$6:$I$35,0,MATCH(C2,Sheet2!$F$5:$I$5,0)),">0")

confirmed with just ENTER..

Both formulas copied across the columns.

Then to extract the products from Sheet2, in Sheet1, C5:

=IF(ROWS($A$1:$A1)>C$3,"",INDEX(Sheet2!$B$6:$B$35,SMALL(IF(INDEX(Sheet2!$F$6:$I$35,0,MATCH(C$2,Sheet2!$F$5:$I$5,0))>0,ROW(Sheet2!$B$6:$B$35)-ROW(Sheet2!$B$6)+1),ROWS($A$1:$A1))))

confirmed with CTRL+SHIFT+ENTER not just ENTER and copied over to next column(s) and down as far as you need to... you will see blanks after all items are extracted.

Hope that is what you were after.