There is a table. 請問這個句子的主詞是There 還是 table? 謝謝。?

That- clause are possible after happen/chanced:-eg:-
It happened/chanced (that) there is a table.
The introductory "it" is the subject.
There is----S+v
a----definite article
table here-------o+adv.
"there" is a pronoun used to show that something exists.
Hence a pronoun can be the subject, not the "table".
"There"a table (in the room).--------obj.
eg:-There are some tables.----------objs.
eg:-There you are , there is what you wanted, a table.--------obj.
In grammar, the noun which is most closely related to the verb in forming a sentence subjectively,adv, is the TABLE;eg:-This is a very subjective judgment of the TABLE here !
If you want to make the subject  TABLE:-
If "there" is an adv. meaning in that place ,then "The table" is there------subject
Also , eg:-Moved please "a table" over there-----subject used subjectively.

🔷《日英辭典》there [副詞] 釋義B. /(弱形) ðɚ｜ðə; (強形) ðeɚ｜ðeə/ [存在を表わす there is の形で] 《★【用法】 there は形式上主語のように扱われるが，動詞の後に通例不特定のものや人を表わす主語が続く; 「そこに」の意味はなく，日本語では there is [are] で「…がある」の意になる》
釋義B-1. [be を述語動詞として].
例. There's a book on the table. テーブルの上に本がある 《★【比較】 The book is on the table. その本はテーブルの上にある》.