Thank you for the log. I remove it from this public accessible forum, though. It could contain private data to your public facing application. Please, when do post follow the best practices to clear the log first before reproducing the problem and erase the private data from it.
On the case - here is an article
that describes how to overcome the System.OutOfMemoryException.
If you do not use the latest internal build - upgrade to version 2016.2.824. There are some performance optimizations that could help in this case. The easiest way to upgrade is from the welcome screen of the UI as it is shown on the attached screenshot.
Let me know if it solves the problem.
Telerik by Progress