Hy, I see that it seems to indeed be called "Mini mercado Furtaria", which is really interesting, since 'Furtaria' is a conjugation of 'Furtar'(to steal). So, either it is intentional or a typo of 'Frutaria'.
In either case, according to the website you provided, to Openstreetmap and to this one(https://www.lisboa.pt/fileadmin/atualidade/noticias/user_upload/Estabelecimentos_Comerciais_Plataforma_de_Restaurantes_e_Comercio_de_Lisboa_26_abril.pdf) it is its official name. I think the note can be closed. Thank you for all your help(I'll leave it open, should you want to comment anything before closing it)!