The Rails convention is to make table names the plural form of the name, and the model as the singular form.
Makes sense when you think about the database. Your posts table contains all the individual post records.
Your Post model is named as such because it is the blueprint for instantiating individual post objects.
Rails will not always generate the table name with an s at the end. The maintainers of Rails understand that some words are irregular (e.g. 'person' and 'people'), and that some words that end in 's', like 'press' would be pluralized by adding an 'es' at the end.
For some cases, Rails isn't quite smart enough and you need to specify the plural form. You give a great example with press. If you do rails g model press, it will created a tabled called presses. But if you mean press as in 'the press', then presses is not really correct.
In this case, you can tell your app what you want when it comes to pluralizing certain words. When you make a new app, you get a file that lives inside of config/initializers/inflections.rb, where you can customize how you want some words to appear. For example, if you wanted 'press' to just remain 'press', you could do:
ActiveSupport::Inflector.inflections(:en) do |inflect|
inflect.irregular 'press', 'press'
end
Now, when you call pluralize on 'press', it will remain 'press'.
Here's a pretty good article on ActiveSupport::Inflector, which gives another example where they want Rails to correctly pluralize specimen since by default, Rails pluralizes it to be the same as the singular.