public class TabViewModel : MultiPageViewModelBase{
        public TabViewModel()
        {
            var parameter1 = "Simple Page";
            var parameter2 = "About Page";
            var items = new List<NavigationItem>();
            items.Add(new NavigationItem("Simple Page", new NavigationTarget(typeof(SimpleViewModel), new NavigationParameter(parameter1))));
            items.Add(new NavigationItem("About", new NavigationTarget(typeof(AboutNavigationViewModel), new NavigationParameter(parameter2))));
            this.Items = items.ToArray();
        }
}

2. The second technique is the dynamic one. You can perform any logic based on your scenario to provide the parameter and pass it to the child's view model. Simply, you only need to override the ShouldNavigate method from the parent's view model. See the following code.

public class TabViewModel : MultiPageViewModelBase
{
        public override bool ShouldNavigate(NavigationTarget target)
        {
            // Perform your own logic here
            if (target.Type == typeof(SimpleViewModel))
                target.Parameter.Data = this.Data1;
            else
                target.Parameter.Data = this.Data2;
            return base.ShouldNavigate(target);
        }
}

Hope this helps. Feel free to discuss it further if you have any other thought.

Kind Regards,

Jack