At some papers, an editorial board meeting means a discussion with an actual board made up of newspaper editors, editorial page writers, and community/corporate representatives. Usually, it just means a meeting with the editors, editorial page writers, and reporters who have an interest in the subject you want to discuss.
Deciding whether to request a meeting. You might want a meeting 1) if you think you can influence their editorial policy and news coverage on a particular issue or campaign – so they will be favorable or at least less unfavorable or perhaps neutral – or 2) if you think you can use the meeting to establish a better long-term relationship.
You may not want a meeting if you think the effect would be to prompt them to write negative editorials when they wouldn’t have written any. In that case, you may just seek space for an op-ed by a community ally or someone from the union.