Add/delete table rows on protected worksheet

I have a spreadsheet with many columns, only two of which should be available for the user to enter data. The data is arranged as a table whose length can vary, from one or two rows to thousands. Initially there is only one empty row containing the formulae. I have applied worksheet protection, allowing access to unlocked cells and the addition or deletion of rows. I find that with worksheet protection switched on I cannot add or delete rows. I could write code to add a row but before I do that I'd like to know if there is any way to configure the table so that rows can be added in the normal manner (ideally just by starting to type in the next row) even when protection is switched on.

Seems to be a bug/undesirable feature of Excel. It seems many requests have been raised om Microsoft to allow adding/deleting rows on protected sheets.