Hello babu,
Quoting the reference guide; After creating a new Table object using the constructor, you usually need to set the table style, number of rows and columns, column width, row height, insert position, width direction, and normal vector. You can also enter text or block contents into each cell using Table methods.
I'm not aware of an actual "update" method, nor does the documentation speak of one.
Just edit the table and maybe do a 'regen', this will most certainly 'update' your table.