Thank you for using Syncfusion products.
We have analyzed the provided PDF document and it contains multiple images in a single page. When the provided PDF document is loaded in the PDF viewer control, the decoding of the multiple images are taken some considerable amount of time to render the pages. Also, if we download all the pages which contain multiple images in the PDF document from the server to the client, there is a chance for a memory exception to occur during the data transfer. However, we will consider to improve the loading time of the PDF viewer when the documents with multiple images are loaded.
Please let us know if you need any further assistance.
Regards, Sabari Anand