EDIT: nevermind, this is not correct.

It appears as though all spreadsheets are grouped together in the same window under tabs. Perhaps its fetching the data for all of them. I noticed they all took a long time to load and then after one loaded, the others had loaded.

I imagine that could be sorted out to load per tab. Im more concerned about the idea of grouping all spreadsheets together. As opposed to a normal website which could embed a datatable in whatever page layout you want.

In general it bothers me to encapsulate what are essentially just page layouts as apps.