Thank you for contacting Syncfusion Support.
We have tried to reproduce the reported issue, but it is working properly. Also, we did not faced this type of issue with HTML to PDF converter. Kindly ensure the table is displayed properly in browsers from the URL/HTML file. WebKit rendering engine internally make use of QtWebKit rendering engine. So, kindly ensure table is preserved properly in WebKit based web browsers (safari).
Kindly share us the input URL/complete HTML file, with code snippet, product version, environment details such as OS, bit version, culture setting etc., to reproduce the issue in our end. So that it will be helpful for us to analyze and assist you further on this.