On the Dataset properties tab, which is present when you have selected a new or existing dataset in a database, you determine the general properties of this dataset.
Click here for information on how to edit properties in general. And click here to read about how to manage objects in the tree view in the Application browser. On the current tab you'll find the following settings:

Dataset name

Enter a name for the dataset. Preferably use lower case letters only: if you don't, know that dataset names are processed case-sensitively.

Lower limit and Upper limit

A dataset is differentiated from other datasets in the database table by the range of its record numbers. You can therefore define a dataset within a database table by specifying the highest and lowest record number for that dataset. The lowest possible number is 1 and the highest possible number is 2,147,483,647. You should select the limits in such a way that there is plenty of room for all the records you want to store in this dataset, now and in the future.

Warning: when you divide up a database table into datasets, make sure the datasets do not overlap.