Hello,
The content of the table is displayed in the DOCX, but as you are inserting the WordFragment in a text content it's being displayed as a run of text (and a table is always a block content).
We recommend you to add the table standalone (as a WordFragment or using addTable directly, but not as a run of text of a paragraph) or add a placeholder and replace it by a table WordFragment using the replaceVariableByWordFragment method.
Regards.