תַּשְׁבֵּץ
The root שׁ.ב.צ (sh.b.ts) means checkered or plaited.
Thus a slot on a calendar is called a מִשְׁבֶּצֶת
and an informal way of saying to book an appointment is לְשַׁבֵּץ פְּגִישָׁה 
For example:
שִׁבַּצְתִּי אֶת הַפְּגִישָׁה שֶׁלָּךְ עִם הַמְּנַהֵל לְתֵּשַׁע וָחֵצִי, זֶה בְּסֵדֶר?
I booked your (a female’s) meeting with the manager (a male) for nine thirty, is that okay?
And the board full of slots called a crossword puzzle is called a תַּשְׁבֵּץ
(in Biblical Hebrew, something plaid).
For example:
סַבְתָּא מְאֹד אוֹהֶבֶת אֶת הַתַּשְׁבֵּצִים שֶׁלָּה.
Grandma loves her crossword puzzles.