"By default, all application scope scripts can read the table's records but cannot perform any other database operations." https://developer.servicenow.com/dev.do#!/learn/learning-plans/tokyo/servicenow_administrator/app_store_learnv2_securingapps_tokyo_application_access_database_settings

* Options for Creating Tables in Guided Application Creator:
* Create a table from scratch: This option allows you to define a completely new table with custom fields and configurations.
* Create a table from a template: You can use predefined table templates to speed up table creation.
Templates often include pre-configured fields and settings.
* Extend a table: This allows you to create a new table by inheriting fields and functionality from an existing table, enabling reuse and consistency.
* Why Other Options Are Incorrect:
* Option A (Link to external tables): Linking to external tables is not an option provided in the Guided Application Creator; external data is typically accessed through integration methods.
* Option D (Run import jobs): Import jobs are used for data migration, not for table creation in the Guided Application Creator.
* Option E (Upload a spreadsheet): While uploading a spreadsheet can create tables, this is a feature of Import Sets, not the Guided Application Creator.
* Option F (Use API calls): API calls are for integration and not an option for creating tables directly in the Guided Application Creator.
ServiceNow Developer Documentation on Guided Application Creator.

Table Extension in ServiceNow:
Extending a table in ServiceNow means creating a child table based on a parent table. The child table inherits the fields, configurations, and functionality of the parent table.
What is Inherited:
Fields: All fields from the parent table are available in the child table.
Functionality: The child table benefits from any business logic or workflows defined for the parent table.
Access Controls: The child table respects the Access Control rules defined for the parent table unless explicitly overridden.
Why Other Options Are Incorrect:
Option B: This is incorrect because the new table does inherit fields from the parent table.
Option C: This is incorrect because you do not need to script or configure behaviors from scratch; they are inherited.
Option D: This is incorrect because Access Controls are not ignored; they still apply and can be extended or modified for the child table.
Reference:
ServiceNow Developer Documentation on Table Inheritance​.