Can Blazor open a URL in a new tab using UriHelper NavigateTo?

You have to use the JS interop to achieve this requirement.

public async Task NavigateToUrlAsync(string url, bool openInNewTab)
    {
        if (openInNewTab)
        {
            await JSRuntime.InvokeAsync<object>("open", url, "_blank");
        }
        else
        {
            this.UriHelper.NavigateTo(url);
        }
    }

Refer to this thread for more information.