The ContentReplacer class itself cannot do this for you. It is aimed at replacing just text and images.
Does
the placeholder occupy a region equal to or greater than the region the
table will occupy? If so, you would remove the placeholder (perhaps
using Redactor), and then place you chart.
https://www.pdftron.com/pdfnet/samplecode.html#PDFRedactAnother
class that might help, is Stamper class. You could add your table to a
temporary Page object (a page not part of the PDF pages) and then use
Stamper class to place the table on the target page for you. Stamper
class alleviates some of the trouble with placing content.
https://www.pdftron.com/pdfnet/samplecode.html#StamperIf
the placeholder is possibly smaller than the table, and there is other
content that needs to be moved to make room, then this is a more
difficult task, as you would need to reflow/move content.
Please clarify