Does he like me? And what is a good way of showing him that im interested without being creepy and weird?

There’s this guy at work. When I first met him I was not attracted to him nor did I think that I would ever talk to him. He is definetly hard to figure out. When we work together he always talks to me and if there is an akward silence he always tries to say something to keep/start a conversation. We did have a lot to talk about and he’s a really nice guy. Too nice. He always tends to look at me and smile. At the same time he is sarcastic and likes to tell jokes. When he looks at me and smiles I definetly look at him and smile back. He always holds the door for me and is extremely honest. However, sometimes when we are with a group of co-workers he is completely silent and dosent really say anything to me nor anybody else. We also had to work on a project together at work and he was the one writing both of our names. he wrote: angela + ______, instead of an "&"....what could this mean?? Does it mean anything when a guy uses “+” with his name and a girls’ name instead of just using &….?? Does this guy like me or is he just being nice?? I REALLY like him and what is a way of showing him that I’m interested without being creepy or actually telling him?