You can perform calculations that span across more than one table in a text document.
Open a text document, insert two tables, and type numbers in a few cells in both tables.
Place your cursor in an empty cell in one of the tables.
Press F2.
In the Formula bar, enter the function that you want to perform, for example, =SUM.
Click in a cell containing a number, press the plus sign (+), and then click in a different cell containing a number.
Press Enter.