I’ve often tried to use MS Word tables and do computations with the values in the tables. Example:

Suppose, the following conditions hold true:
c1 = a1xb1
c2 = a2xb2
a3 = a1 + a2
b3 = b1 + b2
c3 = c2 + c2

Click on the c1 cell, click on the “Layout” button, click on “Formula” button, in the Formula field, enter the following:
=PRODUCT(a1:b1)
Similarly, for c2 use =PRODUCT(a2:b2).
For a3,b3,c3 use =SUM(ABOVE)

While my roommate was doing an excel sheet I came to know of an interesting thing:
If you wanted to transpose rows and columns in an excel file (i.e. interchange rows and columns) just select all the rows and columns that you want to be interchanged and copy them. Then select another cell outside the selected range and right-click. Then click on “Paste Special” and then click on the check box on “Transpose”. That’s it!