If you want a full size foldable keyboard with function keys and a trackpad, I can recommend the ProtoArc XK01[0]. This is a good enough keyboard that I use it as my main keyboard at home, and it's surprisingly cool to be able to just fold up your daily driver keyboard and take it with you.

[0] https://www.protoarc.com/products/xk01-tp-foldable-keyboard-...