Above picture there are some notes are written smaller does it mean play slightly more silent?
does it mean play slightly more silent?
No. It means play that one note as fast as possible. It is called a "grace note" or in the Italian of formal music nomenclature, "acciaccatura". The time it takes to play the note is taken from the next note to which it acts as an ornament.
I'm not a great tab fan, but this looks like it was written by a non-guitarist.
The small notes are grace notes, called 'acciaccatura, which have very little time value themselves - could be almost seen as 'whoops, now I'll play the right note'. Often played slightly quieter than the main following note, wihich would then retain its accent, if needed.
On guitar, it's way more usual to play a grace note and the next note on the same string. If the main note is lower, then it's a pull-off, if it's higher, it's a hammer on (or, more rarely, a slide).
Depicting the two notes to be played on different strings? Well, it's possible, but unusual, and generally won't sound as effective, as well as most guitarists would look and go 'What..?'