OFS
Via Seating
9to5seating
2020 Furniture Design Cambridgeshire
sixteen3 - Sustainability Led Commercial Soft Seating
Modular office furniture & ergonomic chairs
Sutherland Furniture
Lovely outdoor (with indoor possibilities) furniture. Only OBJ and CAD files.
Manutti
Roberti
Outdoor furniture.
Cassina
Talenti
All outdoor, they even have outdoor kitchens
Poliform
MINOTTI
Upscale Italian brand.
S•CAB
Pretty outdoor furniture and lightweight metal interior and work furniture
Blu Dot
Not sure if this is contract grade furniture, but I signed up for a trade account and 3D files and spec sheets are available.
COR
I've used many of their lounge seats, including "Shrimp" and Nenou. They provide downloads here: https://www.cor.de/en/downloads (and on BIMObjects)
Glimakra
Really cute stuff - acoustic hut pod (nice revit file), poufy beanbag chair, tree-like dividers, leaf acoustic hangings, accessories.
True Design
La Cividina
Kristalia
Koleksiyon
iSiMAR
Form & Refine
Only a few revit files (blueprint chair)
Carl Hansen & Søn
Capdell
Boln
Artek
Not all products have Revit files, but there are a few
Actiu
Venue Industries
La Manufacture