There is a great range of materials to choose from including hardwoods, aluminium, rattan, wicker, cast Iron. Consider factors such as weight, maintenance and storage. Aluminium furniture is rust proof but some pieces may be too lightweight for windy climates. Make sure you purchase a heavy aluminium table if wind is an issue.
The eclipse range at Laois Garden world is a great example of this. Synthetic rattans provide a Mediterranean look that withstands Irish weather and teak can be beautiful stained or even left untreated.