Shinui Makom, changing one’s location while eating, has a significant impact on the laws of Berachot. The Halacha depends on several variables, including the degree of change in place and the type of food eaten.
Regarding the food, the Gemara in Pesahim presents a Machloket between Rav Sheshat and Rav Hisdah. Rav Sheshat holds that leaving the original location of eating, requires a new Beracha when he returns. He does not differentiate between bread and other foods. Rav Hisdah argues that if one eats bread, he is always connected to his original place, since he is required to come back to say Birkat Hamazon. Therefore, if he left and returned, he can continue eating without a Beracha. With other foods, that do not require reciting a Beracha Achrona in the original location, leaving the place severs the ties to the original Beracha, and he must recite a new Beracha if he comes back and wants to continue eating.
Rambam and the Shulhan Aruch rule in accordance with Rav Sheshat; Even if one ate bread, leaving his place requires a new Beracha when he returns. The Rosh and the Rema rule in accordance with Rav Hisdah that leaving the place where he ate bread does not sever the connection to the original Beracha.
Even though Maran ruled on this matter, it is still considered a "Safek Berachot"-an uncertainty in the laws of Berachot, since there is a chain of disagreement from the Gemara through the Rishonim up until the Poskim. Therefore, the Halacha is to be lenient in a case of doubt and refrain from making a new Beracha of Hamosi if one left his place while eating bread. The best practice is to avoid entering this problematic situation in the first place by not leaving the place of eating bread. That way, there is no uncertainty at all.
If a person ate fruit, by himself, and then left his house, there is no disagreement. All agree that he must make a new Beracha of Ha’etz when he returns and wants to continue eating. He makes one Beracha Achrona at the end to cover both segments of eating.
SUMMARY
When eating bread, one should avoid leaving his place in the middle, if he intends to return and continue eating. If he did leave, he should not say a new Beracha of Hamosi when he returns to continue eating. When eating fruit by himself, one must recite a new Beracha if he leaves his place and then returns to continue eating.
