Most of the answers here assume a non-blank last line of the file - which is likely the most common case. There are also assumptions about the availability of an END key on one's keyboard. However, END keys are not universally available and blank lines are possible at the end of a file. Therefore the following can be leveraged for all cases to find the last (non-end-of-line) character of a file:
This is merely one of a few (or perhaps several) command combinations that can achieve the intended result. The pattern being:
"Set Cursor Position" + "Search Method" + "Pattern"
In the case of the above command sequence, you go to the end of the file and do a reverse search for any character (but not an 'end of line' character).