This results in a missing paragraph. For example, having a table with three cells and Page field in the footer of a document and exporting it to PDF, will not export the last paragraph.
As a workaround add new run after the last field character in the cell's table before exporting the document to PDF.
BlockCollection footerContent = this.document.Sections.First().Footers.Default.Blocks;
Table footerTable = footerContent.First() as Table;
var cells = footerTable.Rows.Last().Cells.Where(x => x.EnumerateChildrenOfType<FieldCharacter>().Any());
foreach (var cell in cells)
{
cell.Blocks.AddParagraph().Inlines.AddRun();
}