No, it's subject to their [fair usage policy](https://www.eir.ie/opencms/export/sites/default/.content/pdf/terms/eirmobile/fair_usage_policy_v1.pdf){:target="_blank"} which outlines what they consider to be reasonable use.
For example, if you exceeded 120GB data in a 28 day period that could adversely affect other users, they may limit the data speed. You would still be able to access social media sites but streaming services would be slower.