You do, indeed, have a sword from Mainland Southeast Asia, commonly referred to as "dha" in Burmese and "darb", "daab", etc. in Thai. Others here, noteably Wilked, Mark Bowditch and RhysMichael are much more learned on the proper terminology than I.
The lathe-turned handle and polished blade are typical of the swords I've seen coming out of Thailand in recent years. In fact, I have a few very similar ones produced by the now defunct company Aranyik. The quality of this form of sword varies widely from complete tourist garbage to quite good. Your example looks to have some age to it, but I'd venture not much older than late 20th century, based on the lathe-turned handle.
The scabbard is unusual in that the terminus follows the shape of the blade. Usually, these are squared off or rounded. I think I recall somone recently posted another example of a Thai sword with this feature. Prior to this, the only sword of this type with a similar scabbard that I've seen was said to be from Cambodia.
Nice sword. Enjoy it.
