All Poskim agree that if one left the place in which he was eating fruit (or other foods upon which a Beracha Acharona of Boreh Nefashot is recited), when he returns to continue eating, he must make a new Beracha. Maran holds that he must make a new Beracha even if he left other people sitting and eating in the original location. According to Maran, the only case in which leaving others behind makes a difference is when the group was eating bread. However, the Magen Abraham (Rav Abraham Gombiner, Poland, 1637-1682) and the Elyah Rabah disagree. They hold that if other people remained at the table eating fruit, he does not have to make a new Beracha when he returns. This disagreement generates a "Safek Beracha"-an uncertainty with regard to Beracha and the Halacha is to be lenient and refrain from making a Beracha in such a case.
The Poskim state that even leaving one person behind, e.g. his wife, is sufficient to exempt him from making a new Beracha when he returns.
One should avoid entering into a situation of a "Safek Berachot," and therefore he should not leave his home when eating fruit with other people.
SUMMARY
If one left his place while eating fruit, while another person remained at the table, he should not recite a new Beracha when he return s and wants to continue eating.
