So far in this book you've seen how to create and format a basic table of data. That's great for getting started, but as power users, professional accountants, and other Excel jockeys quickly learn, some of the most compelling reasons to use Excel involve multiple tables that share information and interact with each other.
For example, say you want to track the performance of your company: you create one table summarizing your firm's yearly sales, another listing expenses, and a third analyzing profitability and making predictions for the coming year. If you create these tables in different spreadsheet files, you have to copy shared information from one location to another, all without misplacing a number or making a mistake. And what's worse, with data scattered in multiple places, you're missing the chance to use some of Excel's niftiest charting and analytical tools.
On the other hand, if you try cramming a bunch of tables onto the same worksheet page, as shown in Figure 5-1, you can quickly create formatting and cell management problems. Not only do you have to be careful to avoid overlapping data, but if you stack tables on top of each other and then discover you need to add more data to the first table, you have to move the second table. And when you combine multiple tables in a single worksheet, you also have trouble properly resizing or formatting columns, because each column contains data from a different table. Putting tables side by side, separated by a blank column is a somewhat better choice, but it can create problems if you need to add more columns to the first table.
Note: To add new rows and columns and move the rest of your data out of the way, you can use the Insert Rows and Insert Columns commands. But most Excel masters agree that using separate worksheets, described in the next section, for each large table you create is a better solution.