According to MSDN ResXResourceWriter page one can generate such resources using code provided there. Both string and array are serializable types, but of course resources contain Base64-encoded serialized array representation, which is not readable or writeable easily. But it is possible, and the type is detected correctly when adding generated resx file. I've used the following code to test:
using System.Resources;
internal class Program
{
private static void Main(string[] args)
{
var arr = new[] { "Test", "string", "array", "resources" };
using (var writer = new ResXResourceWriter("./output.resx"))
{
writer.AddResource("strings", arr);
writer.Generate();
}
}
}
That said, no, it is not possible to have string array defined inside resource file in human-readable form without additional customizations.