It is actually more straightforward than it looks, just break it down and work it piece by piece and it should make sense.
There are really just a few things you need to know first.
1. How the OFFSET function works. See: https://exceljet.net/excel-functions/excel-offset-function
2. Knowing that ROW() will return the row number from whatever cell that formula is located in.
3. Knowing that COLUMN() will return the current column number from whatever cell that formula is located in.
You can break out the formula and place it in various cells to see what it returns, i.e. =(COLUMN()-30)+(ROW()-6)*14
And can break it down even further, if you like, i.e. =(COLUMN()-30)
Once you see all this, it should make more sense.
Post back if you still have any questions about it after trying this.