the double-helix structure of DNA

[keannu]

[FONT=&#48148]The pub has two small tables, and they are(which are) too hard to book.
They are called “DNA table.”, which was the first discussion place for (the) DNA structure.
James Watson and Francis Crick announced the double-helix structure of DNA in 1953.[/FONT]

Are the underlined correct?

 

[Tarheel]

Perhaps:

The pub has two small tables that are hard to book.

And:

They are called DNA tables because it was there that the structure of DNA was first discussed.

 

[Tarheel]

Perhaps:

In 1953, James Watson and Francis Crick announced that they had discovered the structure of DNA, a double helix.