That's a remarkable idea - it seems to say that a table in 5NF can't have more than 2 attributes. Not surprisingly, that is not correct, for example a historized attribute table in Anchor Model (see the Wikipedia article on Anchor Modelling) has 3 attributes but is in (Date's version of) 6NF and hence also in 5NF.

Gurjer, did you look at the Wikipedia page on 5NF? If so, look at it again but instead of "travelling salesman" think "person with an agency agreement with one or more manufacturers", and instead of "telescope" think "hat stand" - you may well find that the example is much more believable like that, and that will perhaps make it easier to understand. If that doesn't help, say so in this forum and I'll try to find time to do a better explanation for you.