but now every time I add something to my Homepage I have
to mess around with my text boxes
That is one reason why text boxes should be avoided. Unless your entire
page is locked down with absolute positioning you will ALWAYS have problems
with text boxes.
Also, bear in mind that over 20% of web users will never see the text boxes,
since they do not use Internet Explorer. Those users will see a completely
messed up page.
To add a table inside an existing table (nesting), click in the cell you
need the table, then from the menu, Table->Insert Table
Choose the number of rows and columns required.
It often helps to plan the page, or an area within the page, on grid paper
and design your tables and nested tables there.