I'm trying to design a table that has 3 additional tables in the last cell. Like this.

I've managed to get the first nested table into row 4, but my second nested table is going into cell(1,1) of the first table.
var wordApplication = new Word.Application();
wordApplication.Visible = true;
var wordDocument = wordApplication.Documents.Add();
var docRange = wordDocument.Range();
docRange.Tables.Add(docRange, 4, 1);
var mainTable = wordDocument.Tables[1];
mainTable.set_Style("Table Grid");
mainTable.Borders.Enable = 0;
mainTable.PreferredWidthType = Word.WdPreferredWidthType.wdPreferredWidthPercent;
mainTable.PreferredWidth = 100;
docRange.Collapse(Word.WdCollapseDirection.wdCollapseStart);
var phoneRange = mainTable.Cell(4, 1).Range;
phoneRange.Collapse(Word.WdCollapseDirection.wdCollapseStart);
phoneRange.Tables.Add(phoneRange, 3, 2);
var phoneTable = mainTable.Cell(4, 1).Tables[1];
phoneTable.set_Style("Table Grid");
phoneTable.Borders.Enable = 0;
phoneTable.AutoFitBehavior(Word.WdAutoFitBehavior.wdAutoFitContent);
phoneTable.Rows.RelativeHorizontalPosition = Word.WdRelativeHorizontalPosition.wdRelativeHorizontalPositionMargin;
phoneRange.Collapse(Word.WdCollapseDirection.wdCollapseEnd);
I've tried collapsing the range, adding in a paragraph then collapsing the range again. No luck. I found this post and many similar ones, but I must be missing something.
Thanks for your time.

Table.Rows.WrapAroundText = true;)phoneRange.MoveEnd(Word.WdUnits.wdCharacter, -1); phoneRange.Tables.Add(phoneRange, 3, 1);results in error the object refers to the end of a table row -2 results in the table going into the row above. I've tried various combinations but haven't got much further. Thanks for your help so far.