I have written about the famous portugese egg tart in Macau before. The other famous shop that sells tasty portugese egg tart in Macau is Margaret O Nata's.
Margaret's Cafe portugese egg tart is comparable to Lord Stow's bakery in Macau, Coloanne. Which is better? It is difficult to choose between the two but I find Margaret's 'pou tart' ( that's what they would say in Cantonese) is a bit more crispier!
In terms of location, Margaret's Cafe e Nata is located in Macau main island so definitely more convenient for tourists. If you are having trouble finding it, it is near the Grand Emperor Hotel and close to Casino Lisboa approximately 10 minutes walk from there. If you see the jewellery shop called Chow Tai Fook near Casino Lisboa, it is behind this shop located in a small lane.
Margaret's Cafe e Nata
Edificio Kam Loi