Here are the top five Dublin restaurants for solo travelers, according to venere, a European hotel booking site similar to hotels.com. The site chooses these eating establishments for pluses such as:
Avoca: "...the staff won't blink at lone diners..."
Cake Cafe: "...half the city is unaware of it's location so you'll almost always be able to snag a table."
Dunne & Creszenzi: "...no one will rush you through a glass of wine in order to flip a table."
The Bistro: ..."the staff are always solicitous."
But the one that sounds the best to me is:
O'Neill's: "Even as a single diner you won't remain anonymous if you stay at O'Neill's for very long."
Go to the site for more details.