It also shows up in several other contexts:
In addition to all fields listed here, any field saved on the entity will be saved as-is to this table. For example, if you set ent.FavoriteFood = "Steak" before duplicating it, this structure will also contain the field FavoriteFood with the value "Steak".
The entity's position, relative to the duplication origin point.
The entity's angle, relative to the duplication angle.
Data about the entity's PhysObjs, see Entity:GetPhysicsObjectNum. The key is the physics object index (starts from 0), and the value is a PhysicsObjectSave structure. Unlike other tables in this structure, if there are no physics objects for this entity this will be an empty table.
Each flex bone's flex weight, see Entity:GetFlexWeight. The key is the flex's index and the value is the weight. Only flexes with a non-default (nonzero) weight are listed, and if none exist, this field will be nil.
The entity's body groups, see Entity:GetBodygroup. The key is the bodygroup ID and the value is the assigned bodygroup number. Only body groups with a non-default (> 0) value are listed, and if none exist, this field will be nil.
Bone manipulation data, see Entity:HasBoneManipulations. The key is the bone index and the value is a BoneManipulationData structure. Only bones that have been manipulated with non-default values are listed, and if none exist, this field will be nil.