The API should allow the client to navigate to an empty block container and manipulate it.

The block containers are Section, TableCell, Header, Footer, Comment.

The API should also include manipulation methods for a table like:

Add a row to a table.
Add a cell to a row.
Add a table to an empty cell.
Add a paragraph to an empty cell.
Add a run to an empty cell.
add a text to an empty cell.
Move to a next/previous cell.
Move to a next/previous row.

The API should use the currently applied editor formatting when creating the specified document elements.