Power Query refreshes too long without reasons

If you go back to your question, you have the answer.

If your PQ steps are complex or involve intensive calculations, they can significantly slow down the refresh time. Simplify your queries where possible. If you're pulling data from an external source, the performance of that source can impact refresh times.

Even though your Excel file is only 12MB, the volume of data processed during the transformation might be much larger. Power Query may load and process a large amount of data before filtering it down to your final result.