https://cdn.discordapp.com/attachments/611412966327189510/724137520207626351/unknown.png
When I make my eating animation, there's this weird arm gap and I'm wondering if there's a way that I can avoid this but still retain the animation that I want which is a drinking animation.
Since I can't see your animation, this is only an estimation of what you did.
What you have probably done is made the most minimum keyframe possible in the animation, everything inbetween just tries to complete the last keyframe to the next keyframe as soon as possible, possibly making your arm gap you're talking about.
To prevent this, you should add more keyframes inbetween the keyframes where the arm gap appears, and animate them to your liking.