I'm currently working on modernising a program in MS Access into outsystems. I need to transfer the data from the original program, I believed I would have an easy win by exporting all the data into excel files, joining them into  the same workbook and then using the standard import from excel functionality. However after attempting to import the tables, I now have this error

Communication error

There was an error connecting to personal-toigeeol.outsystemscloud.com.

The remote server returned an unexpected response: (413) Request Entity Too Large.

The excel file size was only 1.84MB, which I feel isn't an overly large piece of data. However I have attempted to upload 48 tables at once so can see where the issue probably lies. I know I can create an external database but was hoping that this method would be a bit quicker.

What are the limitations for importing excel files into your outsystems database? Are there better ways to import numerous excel files into an outsystems database? Why is this data amount considered too large?

Also, I'm currently in a personal environment.