There's little to say about these. They are basically the signs or strings or tokens between words which is not WhiteSpace or LineTerminator or Identifier. At this level of the production, they are grouped simply to be matched as a token.
They are: {, }, (, ), [, ], ., ;, ,, <, >, <=, >=, ==, !=, ===, !==, +, -, *, %, ++, --, <<, >>, >>>, &, |, ^, !, ~, &&, ||, ?, :, =, +=, -=, *=, %=, <<=, >>=, >>>=, &=, |=, ^=, /, /=.