Hello, friend!
You can do as follows:
Step 1: On your Huawei tablet, go to Settings > HUAWEI ID > Cloud Space.
Step 2: Choose Manage Cloud Storage > Cloud Backup.
Step 3: Click the name of the device whose backup is to be deleted.
Step 4: Click Delete Backup.
If you want to know more information, see Huawei Consumer Community support.
Hope this can help you!