HI, it bascially check column C if the value is the same count 10 rows, delete anything above 10 rows.

It can delete the whole row if that is easier after 10 rows, doesn't need to delete just Column B

When the value of column C changes restart, count 10 rows, delete rows above 10 until the value of column C changes again,
10 rows, delete, Column C value changes , 10 rows, delete and so on.

I can send some dummy data tomorrow if you need it.

Thanks
M