copy formula and paste it to dynamic table

Hello Experts

I am looking for better way to copy formula and paste it to dynamic table (I don’t know how many rows there is at the table).
The procedure takes long time for the user.
(the table may contain more than 30,000 rows !!).
My suggestion:

Range("B2").Select
ActiveCell.FormulaR1C1 = "=IF(RC[4]=""+"",0,1)"

tblrows = Range("b2").CurrentRegion.Rows.Count

For i = 3 To tblrows
    Range("b2").Select
    Selection.Copy
    Range("b" & i).Select
    ActiveSheet.Paste
Next i