I never used Tiled software myself. Does it have an option to save or export the map in one of these formats - TMX, XML, JSON?
In Construct 3 first you need to import tileset image into the TileMap object, adjust tile size. If you were able to get TMX file from Tiled, you can try to load it in the Tilemap toolbar. If successful, this should load your entire map.
.
If you don't have TMX file, it still may be possible to import the map. Please share whatever files you got from Tiled and I'll see what can be done.