There are two different options for adding sample data in SAP Business Application Studio1:

• Import for Entity: This option allows you to import sample data from a CSV file for a specific entity. You can use this option if you have a predefined set of data that you want to use for testing or demonstration purposes. You need to download the CSV file from a source, rename it to match the project and entity names, and then select the Import for Entity option from the Add Sample Data dialog. You can then choose the file and import it to the entity.
• Create for Entity: This option allows you to create sample data manually for a specific entity. You can use this option if you want to enter your own data or generate mock data for testing or demonstration purposes. You need to select the Create for Entity option from the Add Sample Data dialog, and then enter the number of rows and the values for each property. You can also turn on the Mock Data option to automatically generate random values for each property.

You do not have the following options for adding sample data in SAP Business Application Studio:

• Import for Service: This option does not exist in SAP Business Application Studio. You cannot import sample data for a service, but only for an entity. A service is a logical grouping of entities that exposes them as an OData API. You can only import sample data for each entity individually.
• Create for Service: This option does not exist in SAP Business Application Studio. You cannot create sample data for a service, but only for an entity. A service is a logical grouping of entities that exposes them as an OData API. You can only create sample data for each entity individually.

References:

• 1: Adding Sample Data - SAP Learning

The dev space types available in SAP Business Application Studio are:

• Basic: This dev space type contains the SAP basic tools extension. It is suitable for developing applications that do not require any specific tools or runtimes1
• SAP HANA Native Application: This dev space type is intended for developing and deploying native SAP HANA applications or analytical models. It contains a comprehensive set of editors and tools to support the creation of database artifacts, such as calculation views, tables, SQLScript procedures, and more2
• Full Stack Applications with Productivity Tools: This dev space type is intended for developing, testing, building, and deploying applications using high productivity tools. It supports various application types, such as SAP Fiori, SAP Cloud Application Programming Model, Java, and Node.js. It also includes features such as application wizard, page map, project explorer, and simplified Git3

References: 1: Dev Space Types | SAP Help Portal 2: Dev Space Types | SAP Help Portal 3: Dev Space Types | SAP Help Portal

You would use the Project Explorer in SAP Business Application Studio to view the logical components of an SAP project. The Project Explorer displays application components in a logical view, which simplifies browsing of the contents of your application. It gives you a bird’s-eye view of the components involved in your application at any point in time. You can see the data models, services, UI front ends, and external resources of your project, as well as the connections and dependencies between them. You can also use the Project Explorer to open the relevant files for editing or previewing your application1

References: 1: Project Explorer | SAP Help Portal