Any collection and arrangement in a condensed form of many particulars or values, for ready reference, as of weights, measures, currency, specific gravities, etc.; also, a series of numbers following some law, and expressing particular values corresponding to certain other numbers on which they depend, and by means of which they are taken out for use in computations; as, tables of logarithms, sines, tangents, squares, cubes, etc.; annuity tables; interest tables; astronomical tables, etc.
All of the items you add to your catalog must be placed within a table -- if you don't create any tables, all of your items will be placed within "Default-table". If you like, however, you can create your own tables to help you manage your inventory more efficiently. When you create a table, you get to decide what fields are available to you when you add items to that table. If you sell a large number of new and used books, for example, you might want to create a special "Books" table. You could include fields especially relevant to books, like an "ISBN" field or a "Reading Level" field that would allow you to indicate the book's target audience. If you also sold records and tapes, you could then create a separate table including fields more relevant to those items.