I'm not an expert on the geography of Spain, and it's rare that I'd defend Grokipedia but in this case I think it is correct.

Meseta Central mean central tableland. Segovia is on the edge of the mountain range that surrounds that tableland, but often referred to as part of it. This is fuzzy though.

Wikipedia says: The Meseta Central (lit. 'central tableland', sometimes referred to in English as Inner Plateau) is one of the basic geographical units of the Iberian Peninsula. It consists of a plateau covering a large part of the latter's interior.[1]

Looking at the map you linked the flat part is between 610 to 760 meters.

Finally, when speaking about the Iberian Peninsula Wikipedia itself includes this:

> "About three quarters of that rough octagon is the Meseta Central, a vast plateau ranging from 610 to 760 m in altitude."[2]

[1] https://en.wikipedia.org/wiki/Meseta_Central

[2] https://en.wikipedia.org/wiki/Iberian_Peninsula