Word documents with large tables/charts embedded in them may not display properly in the document viewer inside D2L. This includes on the grading screen, and this is a known issue.
If it is important that these items display as intended, it is recommended that the files be saved and uploaded as PDF files.
Please note that if the Word file is downloaded and viewed in the native Word application, the tables and charts do render correctly.
More information on using the Content area of D2L can be found here.