While Eventable by default creates a "feed" in your users' calendars (you can read more on why we do that here), you do have the ability to create Add to Calendar buttons that simply download a static ics calendar file.
WARNING: Using this method means that you will be unable to dynamically update events afterwards and will not receive any analytics (i.e. how many people have added to calendar). Please ensure that you are comfortable with this tradeoff before proceeding.
To implement this, follow these steps:
Go to the Events page and click Share Event next to the event you would like to use
In the Email tab, select Plain Text as your email type
Now, hover over the button for Google Calendar, right-click it, and choose Copy Link Address
Paste the link into Notepad (or any simple text editor) and replace "gcal" with "download"
Your link should now look something like this:
You can now use that link to create your own Add to Calendar button that will download an ics file to your users' devices.
You can see an example of what a resulting button should look like here.
Remember, this link will create a static file that cannot be edited/updated afterwards, so make sure that your event content is finalized before sending out your link.