AzureRmStorageTable | sample module to manipulate Azure Storage Table rows

I need an advice how to upload a large csv file (about one minion lines) into a Azure table storage with PowerShell. I am aware about Add-AzTableRow -table $using:table -partitionKey $partitionKey -rowKey $rowKey -property $tableProperty

https://github.com/paulomarquesc/AzureRmStorageTable/tree/master/docs

Based on tests with a smaller file with 10 000 lines it takes about 10 min to upload, processing sequentially. (It should be about 16-20 hours for 1 000 000 lines)

I have tried the smaller file (10 000 lines) with PowerShell 7 to use Foreach-Object -Parallel, but the funny thing is that it takes about 3 times more. From three tests, two uploaded 10 000 lines of file for about 30 mins, one for 47 mins.

Just for comparison, I took less than an hour to upload the one minion lines file with Storage Explorer! So I was wondering what is the process they are using and could it be used with PowerShell?

I have reviewed the following article:

https://blog.kloud.com.au/2019/02/05/loading-and-querying-data-in-azure-table-storage-using-powershell/

Which should be working, but it returns an error with: $table.CloudTable.ExecuteBatch($batchOperation)

So my question would be: Is there any way to load data into Azure table storage in parallel?

As requested, adding the code used.

Note: Code works just fine, but it takes time and I believe It could be faster. Looking for suggestions how to improve.