\hline can be without preceeded
\hlines need to be written as
Edit: Sorry, my answer was only "LaTeX-like" answer to the LaTeX question. It means "do this and don't think about it". I try to improve this now. You can ask why there is the error message "Misplaced
\hline macro is implemented by
\noalign TeX primitive. This primitive enables to put a material between lines of the table and it can be used only after
\cr. This is another primitve which ends the current line in the table or it ends the tab declaration data before the first line of the table. The
\cr is equivalent with
\\ in LaTeX
This is the reason, why I knew your problem without any trying or running LaTeX. The error message was sufficient for me. But the knowledge about such error messages cannot be found in LaTeX manuals. You need to know the TeX itself. This is the reason why LaTeX with TeX error messages is very inhospitable for LaTeX users.
What does mean the message "Extra alignment tab has been changed to
\cr?" You are using
& separator between columns but the number of such columns in the current line of table is greater than is allowed by tab declaration data. The
\cr means the end of line in the table as mentioned above.
The other mentioned error messages are only spread errors.