Why did Excel change the formula?

Well, the formula for cell D1 is

="LOOKUP"(B2,G2:G4,H2:H4).

The formula for cell D8 is now:

="LOOKUP"(B8,G8:G10,H8:H10)

Excel has changed B2 to B8, which is what we want. Cell D8 is in row 8, so we want to look up the Product name in B8, not B2. So that is no problem.

The problem is with the other entries in the formula. Excel has changed them as well. But we don't want them to change. We want Excel to always look up the values by looking in the table that starts in G2.

How do we tell Excel to not change the cell addresses for the table?