Here is a solution, two actually. I think the first of the two is the better solution. You will have to adapt the formulas to your document and tables. If you use a comma for a decimal separator (not the decimal "point"), you will have to change the commas in the formulas to semicolons.

Formulas are:
OFFSET Formula Table cell C2 =OFFSET(Table 1::$A$1,MATCH(A2,Table 1::$A,0)−1,MATCH(B2,Table 1::$1:$1,0)−1)
fill down to complete the table.
INDEX Formula table cell C2 =INDEX(Table 1::A:G,MATCH(A2,Table 1::$A,0),MATCH(B2,Table 1::$1:$1,0))
Fill down to complete the table
The last sentence in the comment in the screenshot means that if you replace Table 1::A:G with Table 1::1:6 in the "index" formula, it will let you add new columns to the data table but not new rows. With Table 1::A:G you can add rows but not columns. The OFFSET formula lets you do both so it is probably the better of the two solutions.