Doing a simple thing like adding a line before an MS Word table or even a WordPress table is not simple sometimes!If you are unlucky and have a table right at the top of the page inserting a line can be a pain. This should be on the context menu (right click menu) but with the solution below inserting a line in the first cell is now possible.
Use this procedure to insert a blank line before a table that is on the first line of the first page in a document.
You can also have the same problem with WordPress.
In this case simply switch to "Text" mode and then add any alphabetical character above the table (indicated by the <table> tag). Continue editing by switching to "Visual" mode.