I have brought these four paragraphs of Section 263 together because they are quite straightforward and need very little explanation.
Paragraph 6: As we have seen several time, everyone is required to have a light burning on Shabbat "in their room" - that is to say, at least in the room where they will sleep (or eat). Therefore people who are spending Shabbat away from home cannot rely on the candles being lit back home but must light their own and recite the blessing: the whole purpose of the Shabbat candles is Shalom Bayit - so that we will be safe and comfortable where we are staying and not endanger ourselves by bumping into things or falling over things in the dark. However, if a husband and wife are both away from home it is still the wife who gets preference in lighting the Shabbat candles in the place where they are staying.
Paragraph 7: In earlier times it was quite possible that guests would not have a room of their own, but would have to sleep in the dining room or some such arrangement. Rabbi Karo says that in such circumstances they do not light candles of their own but should make a contribution to the cost of the candles which are light by the house-owners. However, there are poskim [halakhic authorities] who make a distinction: if the guest is going to eat all by himself he must make the contribution, but if he will be eating with the family he is to be considered as one of them and has fulfilled his duty in the candles that the woman of the house has lit on behalf of them all. I would imagine that this distinction is now almost meaningless, since we are wont to consider our guests as "part of the family" sitting at the same table.
Paragraph 8: It is possible that several households might wish to band together to celebrate Shabbat in one place. The question then arises as to whether just one set of candles should be lit on behalf of all of them or whether each family should light their own candles. We are always very careful not to recite a blessing when not necessary (so as not to "take God's name in vain"); therefore, says Rabbi Karo, only one person should light the candles with a blessing and all the others will be considered as having fulfilled their duty with that blessing. However, Rabbi Isserles says that Ashkenazi Jews do not accept his ruling. The woman of each household lights her own lights and says the blessing: the more lights that are lit the greater the radiance and thus the greater the Shalom Bayit and all the greater the joyous atmosphere that is created. (In the days before electricity it would have been sensible for each set of lights to be light in a different part of the house or room, so that the light would be spread.)
Paragraph 9: In earlier times, it seems, people were sometimes wont to eat their Shabbat meal in the courtyard and not inside the house. This may have been prompted by extreme heat inside or even an excess of flies and other insects. They would light their candles in an angle of the building so that the angle would shield the candles from wind etc, and set their table where the candles could shed their light. The regulation that is given in this paragraph is valid not only for such a situation but also in all circumstances: the candles must be of sufficient size when they are lit for them to continue shedding their light until the complete onset of darkness at the very least.