A Prism project can contain many data tables.There are three ways to create a new table
Click the new button from the Sheet section of the Prism toolbar (or drop the Insert menu) and choose New Data Table and Graph.
The New Data Table and Graph dialog looks a lot like the Welcome (File..New) dialog (with fewer choices). Choose which of seven kinds of data tables you want, and whether to start with an empty table or use sample data. If you choose to create an XY or Grouped table and are not using sample data, you'll also need to decide about subcolumn format.
From the navigator
New to Prism 8, click a link in the navigator to create a new sheet.
Duplicate an existing table
To duplicate an existing table, to to that table, drop the Insert menu or click the New button and choose Duplicate Current Sheet