"Qe'Daq 'oHtaH raS'e'."
Translation:The table is in the restaurant.
Personally, with location sentences, a sentence with a definite subject feels different to me than a sentence with an indefinite subject.
With a definite subject (one that is marked as definite by the definite article "the", a demonstrative determiner such as "this" or "that", or a possessive such as "my"), you already know what you're talking about and now you're giving some additional information, namely where it is.
With an indefinite subject (one that is marked as indefinite by the indefinite article "a" or, for plurals, the absence of an article), you're introducing something new -- and it would feel odd to me to give two pieces of new information (the subject and the location) at once. It feels more natural to me to imply that the location is known and the subject is new.
So I would translate "The table is in the restaurant" as Qe'Daq 'oHtaH raS'e' and "There is a table in the restaurant" as Qe'Daq raS tu'lu'.
"A table is in the restaurant" would sound a little odd to me in English but I would understand it the same way as "There is a table in the restaurant", and the tu'lu' version feels more natural to me than the raS'e' one.
"As for the table: it's in the restaurant" feels fine to me in a way that "As for a table: it's in the restaurant" does not.
You are misusing the term indefinite subject. This phrase means the subject is unknown or not mentioned. The Klingon sentence naDev qama'pu' lupollu' Prisoners are kept here is an example of indefinite subject. (It's the -lu' suffix.)
I reject your argument about the English translation of this sentence. You just lack the correct context to make such an interpretation make sense.
Suppose you're a Klingon child practicing talking about where everyday objects belong.
ghopDaq 'oHtaH taj'e'
As for a knife, it is in the hand.
A knife is in the hand.
juHDaq 'oHtaH Saj'e'
As for a pet, it is in the home.
A pet is in the home.
Qe'Daq 'oHtaH raS'e'
As for a table, it is in the restaurant.
A table is in the restaurant.
It just needs the right context and suddenly it's perfectly fine.
In other words, Lee, your sentence was perfectly fine.
In English grammar, "indefinite subject" means an indefinite pronoun (one, someone, none, some, many, etc.) is used as the subject. What you're describing is using an indefinite article (a, an) on a noun, which to my knowledge has no dedicated name.