Are there either tables or lamps that are not made of metal?
No, there is a table but it is made of metal.
    src        edge_attr  dst
0     0  to the right of    3
1     0  to the right of    6
2     0  to the right of    5
3     0  to the right of    2
4     0  to the right of    1
5     1   to the left of    4
6     1   to the left of    0
7     2   to the left of    0
8     3   to the left of    0
9     3   to the left of    4
10    4  to the right of    1
11    4  to the right of    3
12    5   to the left of    0
13    6   to the left of    0