From the command line, as each instruction is typed in, it is executed. A semi-colon is not necessary at the end of each line. The results are, in theory, identical, whether the commands are in a file or typed in one at a time. The command line actually uses the file editor when taking instructions from the user. PageUp and PageDown move around the file one screen at a time.
End works just the same going forwards through the file.
Delete and BackSpace work as normal. ALT-L selects a block, so that groups of lines can be cut or copied and then inserted. Only one block is kept in the delete buffer at one time , so deleting one line and then another means that the first is lost for good, whereas the second can be recovered repeatedly. Four other useful functions.