Foldable laptop?

Is there a laptop that can be folded up to be the size of an iPad?

There's only one answer to this: no. Technically, this is currently an impossibility.

A logitech keyboard for an ipad for example.

or convertables like IdeaPad Flex or Vivobook.

or netbooks.

https://www.stern.de/vergleich/netbook/#Netbook-was-ist-das

therefore yes, there are, at different prices and with different advantages & disadvantages or restrictions.

Has it been a while, at least as far as the screen dimensions are concerned, the thickness was significantly larger. These things were called netbooks, the first netbook was the Eee PC from Asus:

https://de.wikipedia.org/...sus_Eee_PC At the beginning these things had displays with a diagonal of less than 9 ", later they became a bit larger. Gradually, however, they were replaced by tablets, and now you can find them no more netbooks and notebooks have displays from 12 ".