Hi Dara,
Thank you for contacting Syncfusion support,
We have checked the reported issue with a large HTML file in HTML to PDF conversion. While loading the large HTML file in the Webkit rendering engine with millions of table rows of data, the conversion fails in the Webkit rendering engine itself. So, we are unable to proceed further on this.
However, as a workaround, you can split the large HTML files to perform conversion and after the conversion, you can merge the PDF documents using the merge pdf functionality. Kindly refer to the below link for more information,
HTML to PDF: Converting HTML to PDF with WebKit engine | Syncfusion
Merge PDF: Merge PDF Documents | Syncfusion
Regards,
Karmegam