How do I construct a TABLE with specified row heights and column widths?

Ultimately, I wish to construct a SUDOKU grid: 9 rows by 9 columns, forming 81 cells, all SQUARE. Another important Sudoku entity is the BOX: The Sudoku grid consists of a 3x3 array of boxes where each box consists of a 3x3 array of cells. The borders of the box are double that of an interior cell (and are important visual aids in problem solving)

Because of the borders. it may be easier to first construct a 3x3 celled box. Then clone the box to form a 3x3 grid of boxes.

Eventually, a single number will be centered inside each cell. The cell dimensions will have to be coordinated with the font sizes; e.g., the cell-to-cell midpoints will have to be some multiple of character size (for horizontal balance). Also vertical spacing between lines has to be compatible.

for now, I will be happy if I can construct a 3x3 table with rows 0.5" in height and columns 0.5" in width.

Thank you in advance - Bob Thompson