Since both Fusion Tables and spreadsheets show data in a table, how do you know which one to use?
What sort of data do you have?
Data that's a good fit for Fusion Tables will have all the same type of information in any given column. For example, one column will contain people's first names, another column will have a timestamp for each time they called. There's no inherent order to the rows in Fusion Tables...you can sort them by any column.
Many people begin by creating or working with this type of data in a spreadsheet. As it gets bigger, it's more convenient to use the types of tools Fusion Tables offers.
Spreadsheets preserve complete flexibility in managing data -- you can put any value you want in any cell on the grid. You can display many small tables of data on the same sheet, and use grid cells for footnotes or titles.
How big is your data?
Fusion Tables, like other database systems, helps you manage larger amounts of data than spreadsheets typically do. This size difference leads to a focus on a different set of functionalities.
For example, Fusion Tables focuses more on bulk operations on the data (filtering, aggregation, merges). These operations are typically not necessary for smaller collections of data stored in spreadsheets.
How do you want to look at your data?
Spreadsheets preserve complete flexibility in managing data -- you can put any value you want in any cell. By adding background color, choosing text color and cell borders, choosing column widths and even merging cells, you can work carefully to format your spreadsheet to make the grid look nice.
In contrast, rows in Fusion Tables are shown in a default table layout with column headers. However, the new version of Fusion Tables offers a Card layout that makes it simple for you to use HTML to define any layout for your data fields, and use .css styling too. Thus you can create a custom display for the data in each row.
Sometimes there are more effective ways to look at your data than rows in a table. For example, when your data contains geographical locations, viewing the data on a map may reveal patterns that are otherwise very hard to see. Fusion Tables offers several visualizations that will help you explore your data more effectively. Originally under the "Visualize" menu, these are now available in the [+] menu in the new Fusion Tables.
How is your data changing?
Fusion Tables is great at accepting edits to a row of data, and propagating these changes to all the places that data is being used. You can also easily import more rows or update an entire table with new values.
If you're still swapping values around on a grid of table cells or otherwise changing a lot of values, you'll be happier completing that work in a spreadsheet before you import to Fusion Tables.
How do you want to use your data?
When you're collaborating on data with other people, Fusion Tables allows you to filter for just the relevant rows and then share with others.
Finally, Fusion Tables allows you to combine data owned by different parties to make a new table. The visualizations and queries on that table can incorporate any or all of the data seamlessly.