Data Loader Stuck at 'initializing records' Using a CSV File

Data Loader encounters an error at the 'initializing records' stage if the CSV contains blank columns or rows.

Data Loader takes a long time to read the CSV file because some cells beyond the designated columns for import might have content. Deleting all columns (although appearing to be blank) after the last column intended for import will result in the file being read without any issue. This applies to rows as well.

You may also be prompted with a warning pop up, "An empty column is found. Would you like to continue?"

Deleting rows won't necessarily prevent the error as the issue is primarily caused by an empty column without column header. Data Loader recognizes this empty column as data but could not find a header (which should be mapped to the Salesforce field).