The quick answer is that you could use array formulas.
P3:
Your P3 formula, =AVERAGEIF(Table13[Product],$A3,Scores), returns the same result as =AVERAGEIF(Table13[Product],$A3,INDEX(Scores,0,1)), so it appears AVERAGEIF constrains its 3rd argument to the same size as its 1st argument. FWIW, =AVERAGEIFS(Scores,Table13[Product],$A3) returns #VALUE! . This isn't how I recall it working in previous Excel versions, but I don't have any others with which to test at the moment, only Office 365.
Usually I'd suggest SUMPRODUCT instead, but in this case you also have text N/A values in Scores, which scuppers a single SUMPRODUCT call, though you could use
P3:
however, the array formula above is more efficient.
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