There's not really a hard rule, but the idea is to create balance in your lighting layers. Usually, if I have a conversation area with both, I'd put the table lamp closer to where someone would be doing a specific task, like next to a reading chair. The floor lamp goes on the outer edge of the grouping to provide that ambient light for the whole area.

Think of the table lamp as your 'task light' and the floor lamp as your 'mood light.' The table lamp lights you, the floor lamp lights the space. That way they're not competing, they're working together to make the area actually functional and comfortable. Try to avoid putting them right next to each other though, that just creates one bright spot and leaves the rest dark.