Thanks for asking.
On my end grids are loading fine but I can definitely see a bit of lag in page load time. Now part of the reason is that you are using quite a bit of heavy images. Now there is no harm in using high resolution images but it does slow down the website load time. My recomendation would be that you resize the image resolution to reduce the file size. https://cloudup.com/ceGh07E7oIE
First I would suggest you to implement cache plugin on the website. To help you do that we have published article in knowledge base that can be referred:
Please let us know how it goes.