You have pretty much got it split out right in terms of how to put it into a database with a small modification
Code:
tblPart
P_ID P_Description
1 Plywood 2x3
2 60" Legs
3 Plywood 5x5
4 5" Screws
5 Plywood 6x6
6 8" Screws
7 72" Legs
tblProduct
PR_ID PR_Name
1 Chair A
2 Chair B
3 Table A
4 Table B
tblProductPart
PPR_ID PR_ID P_ID Qty
1 1 1 6
2 1 2 4
3 1 3 2
4 1 4 32
5 2 1 6
6 2 2 4
7 2 3 2
8 2 4 45
etc...
where all of your ID fields are autonumbers, just to make building your primary key easy on you.