No, with this is not much data, the pi, I hope it's a pi 3, could handle with it very good. Of course, you should use proxy_pass and not webdav and fastcgi like I the old times where it wasn't possible to use proxy_pass. And you should use raspbian lite and not raspbian with pixel and small the GPU to 16MB, then the pi is very performant, if you know how the performance was in earlier times you won't believe how the performance changed.
2 months ago I ran seafile on a pi 2 to try some changes in the interface and with a pi 3 it would be very, very fast.
Edit: If you use Apache, you have to change to nginx when using a pi.