Table lamps can be used in any space, though they are most often found in bedrooms, living rooms and home offices next to sofas, chairs or beds. Although they can act as a primary light fixture, they are most often used as supplemental lighting for more detail-oriented tasks. They also work well in hallways, stairwells and near doorways since they ensure no one trips and falls while walking. In the end, lamp placement is a personal preference: They can and should be placed wherever you need extra light.
Typically, most rooms need two table lamps, but a larger, open concept space may need many more. To test out your lamp requirements, turn off your overhead light and turn on all your current lights. Walk around the room and see which corners lack light, and determine whether or not those spaces need coverage. It's great to have different levels of light, so even if your main fixture covers good ground, you might want an additional just-in-case options too.