Enter Row Number as a value in cells

ok so I have made things work but not exactly how I want it

I now have the following

With Worksheets("Sheet1").Range("Table1[Item number]")

       Worksheets("Sheet1").Range("Table1[Item number]").SpecialCells _
     (xlCellTypeBlanks).Formula = "=row()-1"
End With

this fills the missing data but with a formula. I can copy paste the who column as values only I guess but as the document grows this will take longer and longer.

is there a better way of getting the value?

thanks