I recently did both the Strategy& and Monitor Deloitte tests in the UK for graduates positions. Both sets of tests are pretty different and I would recommend different approaches for both. For Strategy& I would recommend using Assessmentday.com (https://www.assessmentday.co.uk/). They have a great range of tests covering numerical, verbal, data interpretation and etc. The Strategy& test are very similar to the ones on there and were perfect for preparation.
Monitor Deloitte have started using a 'job simulation' test which is pretty unique. It's a combination of verbal, numerical, situation judgment and data interpretation all combined into one test. The test is broken up into separate stages which are based on different situations you might encounter in the workplace - simulating the job environment. The process is relatively new and as a result, there isn't much material available online. Please feel free to send me a message if you would like to discuss in more detail.
Best of luck with the upcoming test!