The following commands are accessible by right-clicking on a Package element in the model browser.

SysML element creation commands available on a Package
SysML diagram: Launch the SyML diagram creation wizard.
Block: Creates a Block.
Constraint block: Creates a ConstraintBlock.
Flow specification: Creates a FlowSpecification.
Quantity kind: Creates a QuantityKind.
Unit: Creates a Unit.
Value type: Creates a ValueType.
View: Creates a View.
Viewpoint: Creates Viewpoint.