An alternative way to insert a table is to turn it into an image.
There are many ways to convert a table/chart into an image, it will depend on the program in which you made the table, but a good idea would be a screenshot.
To insert an image into your emails visit FAQ: How do I insert an image into my emails?
To insert a table in our Drag & Drop Editor we recommend you do this as an image. To edit HTML code in Drag & Drop Editor visit: How do I view the HTML code?