In case the name wasn’t obvious, Suggestions is kind of like autocomplete for Google where you begin typing something, and based on that it will offer suggestions on what it thinks you’re trying to look for. Since this is sent to a server, it has been suggested by some that there could be a bug in the server request which is causing the app to crash randomly.
The good news is that since this is a backend issue, users will not have to do anything on their end and will just need to wait for Apple to fix it on theirs. However if the problem is getting a bit too troublesome or out of hand, there are some ways to go about it until it is fixed, and one of those methods is to disable Safari Suggestions.
An alternative is to launch the app in Private Browsing mode which offers the same fix. Another way would be to just use a different browser until the problem is resolved.