What is an example of practical scenario when we might need to disable 'Enable load' of the table in Power Query editor? Does it work the same as deleting the table from the entire data model? If so, why keeping a weed?
@teylyn is correct. One of the primary uses for these tables is for storing tables that are only used for building up the ones that you actually want to load into your model.
For example, if you have two tables A and B but you're really interested in their union C = A ∪ B, then you can append A and B in the query editor to create a new table C (not a DAX union after loading) and only load that table to your model by unchecking 'Enable load' on A and B.
This helps keep your model cleaner and your PBIX smaller since the intermediate staging tables are only stored as connections rather than having to store the data they contain too. Tables that aren't loaded to the model obviously can't be used in visuals or referenced outside of the query editor but they behave just like any other table within the query editor.