Shortcut to Entering Formulas Cell By Cell In Large Table?

[Coachcasa]

Hi everyone. I'm working on a large table that is compiling data from another sheet. The table has 2,025 cells in it (45 rows by 45 columns) and each cell has a unique formula. All of the cells have an AVERAGEIF formula that uses 5 variables that it is pulling data from. Each row has 3 variables that are the same, but then every 3 columns in that row have 1 other similar variable and each cell in that 3 column block adds 1 more unique variable (which repeats each 3 cell column block. Right now I'm going row by row and after I create the formula in the first 3 cells in the row, I am copying 3 cells at a time to the next block of 3 and then changing two of the variable in each cell's formula. This is VERY tedious and will take a long time! I do a few rows at a time and then go to some other work before coming back and doing a few more rows. Is there any way to speed up this process and do whole rows or columns or blocks at the same time? I don't think there is because each cell is unique using the five variables. Here is an example of what I'm talking about. I've taken a screenshot of just a small part of the table. It continues this pattern on for a much bigger table. Thanks for any help you can offer.