Last tested: May 2020
This Help Center explains why a query can crash your browser but be fine on the instance and/or database.
The rule of thumb is that 30,000 cells will choke most browsers. You could also crash a browser with one cell that has an incredibly large amount of text inside.
At some point, you have to wonder if you're going to benefit from seeing all that data on the browser. Consider limiting or filtering the data, choosing less measures or pivot columns, or further aggregating the data. Downloading the data would also alleviate the browser problem.
Other things to check:
It could be that the explore actually has hundreds of fields, but all are marked
hidden: yes in the LookML. This will keep them from showing up in the UI, but the definitions of the fields may still be transmitted, and cost something to manipulate in the frontend. Or you have an incredibly large set detail and you need to limit.
Do you have the ability to load the affected explore in your own browser? Doing so with the Chrome developer tools open will let you see the real size/times of network requests like the 'explore' object.
This content is subject to limited support.