Tables

Protecting the whole table

Protecting individual cells

There is no easy way to protect individual cells in a table.
However you can achieve the desired affect by creating a Form and using Text Form Fields.
Insert a Text Form Field into every cell that you don't want protected.
Select (Developer tab)(Protect, Restrict Editing, Protect Document), choose "Filling in Forms" and select "Start ENforcing Protection".
You will have to protect the whole document though.

Important

An alternative would be to create an Excel workbook/worksheet with the desired protection and then insert that portion into your document.