Thank you for contacting us.
I have tested such scenario with loading an Access database with 22000 records and the form loads for about 2.6 seconds. Most of this time is spend in the Fill method of the table adapter which retrieves the data from the database. Also, you say that the performance increases when you filter the results. This makes me think that the problem might be caused by slow access to your database file.
I have attached the project I used for testing this locally. You can use test it to compare the performances (when you first open the form, click "Add lots", then click "Save", close the form and open it again).
If you are still experiencing difficulties, you can open a new support ticket and send us the project you used for testing. This will let us investigate it, test it locally and try to isolate any performance issues if there are such.
Please let me know whenever you have any development on this case. Also, if you have any additional questions, feel free to ask.
All the best,
the Telerik team