Check the video out:
For example, if you were viewing a vehicle record and you navigated to the Fuel tab, you would see an embed of the Fuel table, filtered to only show fuel transactions for the vehicle you are viewing, and an embed of the Fuel Keys/Cards table, filtered to only show fuel cards assigned to the vehicle you are viewing.
Some embed tables reflect tables from the menu bar, as in the example above, and are just for viewing purposes, i.e. you can't add or delete records via the embed. Conversely, some embed tables aren't available from the menu bar, and you can add and delete records via the embed. An example here would be the Vehicle Options table on the Procurement tab in a vehicle record.
If you're able to add and delete records in an embed table you will see the appropriate buttons in the top right corner of the table, and these function in the same way as the primary add/archive/delete buttons - see Archiving & Deleting.
While embed tables don't have the same amount of functionality as browse tables, what they do have, such as sorting, locking and filtering, functions in the same way as browse tables - see FleetWave Browse 1 and FleetWave Browse 2.