Adds assignment to tables

UpsilonTests/TableTests.cs

@@ -153,6 +153,21 @@ table = {
     end
 }
 return table[1]()
+";
+            var script = new Script(input);
+            Assert.Empty(script.Diagnostics.Messages);
+            var evaluated = script.Evaluate<long>();
+            Assert.Empty(script.Diagnostics.Messages);
+            Assert.Equal(400, evaluated);
+        }
+
+        [Fact]
+        public void AssignToTable()
+        {
+            const string input = @"
+table = {}
+table[1] = 400
+return table[1]
 ";
             var script = new Script(input);
             Assert.Empty(script.Diagnostics.Messages);