Does unchecking enable load have impact on refresh?

I'm looking at an example where the enable load is unchecked. This automatically grays out the include in report refresh option.

So it neither loads into the model nor does it refresh this table.

However anywhere else where I use this table (example: merge), I can see latest data. How is this working?

PQ works by using streaming semantics (you can read much more here:https://bengribaudo.com/blog/2020/08/26/5417/how-power-query-thinks). What this means is that nothing is ever cached - PQ always has to stream the latest data from source as it has no where else to retrieve it. Enable load simply loads the table into the data model - if this is unchecked, then it will not be loaded into the data model. Include in report refresh will prevent this table being refreshed if it is already in the data model i.e. it will remain untouched.

Enable load just means whether it is in the data model. If Enable load is unchecked, then the other option is irrelevant. If enable load is checked (the table is in the data model), and include in report refresh is checked, it will be refreshed. If enable load is checked (the table is in the data model), and include in report refresh is unchecked, it will not be refreshed. Those are the only options.