Hi,
If you have a big number of variant, the best is to remove some characteristics and use "options" instead.
To solve the issue, there is nothing special to do in HikaShop, you should increase the memory limitation in your server.
You already have a 128MB limitation which is already pretty high but you have to understand that you server have to load the 1799 products in his memory to generate the page, it can be CPU & memory consuming.
Your error occurred in the Mysqli driver, it means that your server was retrieving the data from the database (and we can't know the amount of data it already retrieve, it can be 99% like it can be 20%).
We will investigate the problem but for most cases we saw, using "options" was a good solution, for the customer side like for the administration side (managing 1799 variants could be very very complex and time consuming).
Regards,