Insert table inside cell in numbers

Maybe your question got lost in translation. To answer what you asked, though, a cell cannot hold a table. You can place a table on top of a cell and it will look like it is in the cell (for the most part) but it is not a good solution. This little "table in a cell" will not be part of the bigger table and will not move around to stay in the cell if you add/delete rows/columns or move the bigger table. I do not see the point or a reason to do this.