For each table in google, you can help performance by deleting any empty columns to the right of the last column in the sheet.
You can do the same with the rows.
Delete any empty rows after the last row in each sheet (Appsheet will insert any rows if it needs to).
You can also use a delayed sync so that the user can add a number of rows of data before choosing to synce – reduces the wait.
Here is a snippet from the Support documentation:
How to improve read-only Sync performance Conceptually, there are six ways to improve Sync performance:
Choose an efficient data provider Reduce the amount of data transferred during Sync Reduce the amount of computation (for spreadsheet formulas and virtual columns) performed during Sync Fetch or compute data in parallel (relevant if there are many tables in the app or many expensive virtual columns) Use a fast network (this is relevant for the connection between the device and the AppSheet Server) Make Sync happen in the background so that the user does not need to wait for them to complete. These are explained in greater detail in this article. As an app creator, you have many options to control these aspects of Sync performance.
How to improve Sync performance when there are data updates Data captured or updated by the app on a device needs to be sent to the cloud provider backend. This can be one of the slowest aspects of the Sync process because the changes have to be made sequentially (to ensure correctness). Conceptually, there are four ways to improve this aspect of Sync performance:
Reduce the number of updates Reduce the amount of data sent with each update (eg: images captured per row) Reduce the amount of computation (eg: workflow rules) that must happen with each update Apply these changes in the background so that the user does not need to wait for them to complete.
Hope this helps.