how to load an expense item of 1500 lines through spreadsheet

how to load an expense item of 1500 lines through spreadsheet?

I see only key is available for 35 lines. I am unable to copy paste or drag or insert the key or any rows and edit. It throws an error saying the cell is protected and it may require a password to unprotect. But it does not ask for password.

Also , the row status is not editable if I use the spreadsheet once.