Marsha,
I don't quite understand either what you are trying to do or what exactly is in your conversion table. Be aware, however, that FrameMaker will always create elements for the basic components that occur in your tables. The conversion table gives you limited control of how those elements will be tagged, but not whether the elements will exist.
If your conversion table contains rows such as:
| P:CellBody | entry | cellbody |
| TC: | entry | |
You will indeed get nested entry elements. The outer one is the table cell itself and the inner one is the paragraph. FrameMaker does not permit a valid document to use the same element tag for both a cell and a container, so aside from the results not being what you wanted, they are not correct within FrameMaker.
If your table cells contain single paragraphs and you don't want elements for both the cells and the paragraphs, your conversion table doesn't even need to mention the CellBody and CellHeading paragraph tags. In fact, if your table formats use CellBody as the paragraph format for cells in the body of a table and CellHeading as the paragraph format for cells in the table heading, your EDD doesn't even have to apply the paragraph formats.
Another variation is to include a paragraph tag in a conversion table row for a table cell by combining TC: and P: to match table cells containing particular paragraphs. For example:
creates cell elements named entry from table cells containing paragraphs tagged CellBody. The paragraph within such a cell is not wrapped in an additional element.
One final comment is that TH: in a conversion table refers to the entire table heading; its children are heading rows. The table body analog of TH: is TB:, not TC:.
--Lynne