You can use existing databases for testing purposes. If you are testing queries or just wanting a sample database model, why not have a look at some pre-existing ones?

Here is a website that has a list of links to SQL Server sample databases. It’s from DanylkoWeb.

You can get SQL Server sample databases and code at github.

You can get sample datasets at OData.

Itzik Ben-Gan has a sample database that goes along with his book T-SQL Querying.

There is Northwind, AdventureWorks, Contoso, Foodmart, Worldwide Importers, and Chinook.

In Microsoft 365 versions of Excel you can go to the Analyze Data button to load sample data. It may also be called Ideas. The Analyze Data button is on the Home tab at the far right. Below is a screenshot of part of the sales data. There are 75 rows of data, plus the header row. It’s not a relational database, just a table.