If you want to permanently remove those parcels, start Edit session (Editor Toolbar: Editor -> Start Editing), select parcel and delete.
You can also create a new layer without unwanted parcels:
- select those parcels, right click on layer: Selection -> Switch selection (now you have desired parcels)
- then right click on layer again: Data -> Export Data, make sure that Export type is 'Selected Features'
If you want to just remove parcels from display:
Use Identify tool and note IDs or unique numbers of unwanted parcels.
Then in Layer Properties -> Definition query tab: build an expression like:
[OBJECTID] NOT IN (1,2,3,5)