Consensus database is 7 gigabytes
I'm using the Sia-UI app on my Mac and the file "consensus.db" is taking up 7 gigabytes. What is in that file? Can I delete it safely?
Of course you can delete it.
You can't delete it safely "forever". As this file is the blockchain and to see your actual balance and make a transaction (send SC) the client needs it to be synced with the network.
If you delete it, the client will start syncing it again. From scratch.