reader's column; letters to the editor
Refers to a section in a newspaper, magazine, or website where readers' opinions, questions, or contributions are published.
I submit a letter to the newspaper's reader's column.
Various opinions appear in the reader's column.
読者欄 is a reader-content page in general (which may include letters, essays, or photos), while 投稿欄 emphasizes that the content was actively submitted by readers.
Compound of 読者 (reader) and 欄 (column, section).