Ray, I have tried to reproduce your problem and created a table that looks like this

There may be a better way, but the only way I could repair it was to delete the column with the year in it, and then delete every row under the 2017 calandar.

Then insert a column before the months, add the required number of rows below the existing calendar

Highlight and merge cells to create the layout you want

& finish up with something like this

Sadly I could not find a way to do it without detroying/removing the year column, but that should not be too hard to recreate.

NB please do this on a copy of your project or at least make an export (iwzip) before starting.

For future reference, if you recreate your table by simply using cells instead of a table, you could make it play nice as a responsive site.

Good luck