I've created the assessment tasks for interviews.
Typing will be covered likely in a 'compose a response to this email from a parent', then save it - it'll be either onto a memory stick or a particular area. Use Save As so you don't overwrite the original. They might ask you to 'create a pdf', which is done by picking Save As and then As Type pdf on the dropdown below the filename box.
Excel will probably be a 'add these names & form groups into the spreadsheet, now sort into alphabetical order by form' task - so filling in the fields, then highlight the table, click Data - Filter - Select Form group dropdown to show 7A, highlight rows - Sort - A-Z by Surname. Then save the spreadsheet. Possibly answer a question where you have the answer in the table data - it's likely that there's two children with similar names in the table, so be aware of this, as it's a good test of attention to detail.
They might ask for a handwritten answer to a prioritisation task. As others have said, it's always the safeguarding/life and limb issue that comes first. And if you haven't been trained in it before, the overriding principle of Safeguarding is don't ignore it, don't keep secrets, always report even if they ask you not to.
I've had a couple of interviews where the tasks have been pulled from the internet, rather than created by somebody who does the job - it's not a disaster if there's something you can't quite work out how to do, as long as you can do the majority and can see what you need to learn.
On another, they had somebody pretend to be complaining in a phone call, the key there was to be polite, professional and tell them that you will find out the answer and respond to them at a certain time.
They aren't necessarily looking for somebody who already knows everything, they'll want somebody who can and will learn as they go along, who can adapt to changes (like using a different database) and can think on their feet/will ask questions, rather than panic and shout or cry. If it's a faith school, it's handy to know a bit about the faith concerned and they really like people who are already or are interested in becoming First Aid qualified (likely to be a requirement of your role, by the way).
Personally, I think that one of the most important things is to never use apostrophes for plurals (so it's 'All students go to room 45 at 12pm', not 'all student's go to room 45 at 12am' - yes, I have seen the afternoon times given as am before) and know the difference between your (your choice) and you're (you're going to need to know this).
Honestly, we've taken on people with zero Excel experience on September 1st and they're blasting their way through detailed spreadsheets, running reports on SIMS and teaching other people how to do those things within a few weeks. It's not 'easy', but it's easy to learn. Especially when you're surrounded by people in the business of explaining things so that others can learn.
Good luck!